#include <iostream>

using namespace std;

int main()
{
          int n = 0, m = 0, k = 0, l = 0, a = 0, b = 0;
          cin >> n >> m >> k;
          for (int i = 0; i < n; i++)
          {
                    cin >> l;
                    if (i < m - 1 && k >= l && l > 0)
                    {
                              a = i + 1;
                    }
                    if (i > m - 1 && k >= l && l > 0)
                    {
                              b = i + 1;
                              break;
                    }
          }
          if (a == 0)
          {
                    cout << abs(b - m) * 10;
                    return 0;
          }
          if (b == 0)
          {
                    cout << abs(m - a) * 10;
                    return 0;
          }
          a = min(m - a, b - m) * 10;
          cout << abs(a);
}

#include<iostream>
#include<cmath>
using namespace std;
int main(){
	int n,m,k;
	cin>>n>>m>>k;
	int a;
	m--;
	int mi=10000000;
	for(int i=0;i<n;i++){
		cin>>a;
		if(a<=k&&a){
			mi=min(mi,abs(m-i)*10);
		}
	}
	cout<<mi;
}

#include <iostream>
using namespace std;

int main()
{
	int n, m, k;
	cin >> n >> m >> k;
	int *a = new int[n+1];
	for(int i = 1;i <= n; i++)
		cin >> a[i];
	int c1 = 0, c2 = 0;
	int i = m, j = m;
	bool f1 = true, f2 = true;
	while(i <= n || j > 0){
		if(a[i] <= k && a[i] != 0 && i <= n && f1){
			c1 = (i-m)*10;
		//	cout << a[i] << endl;
			f1 = false;
		}
		if(a[j] <= k && a[j] != 0 && j >0 && f2){
			c2 = (m-j)*10;
		//	cout << a[j] << endl;
			f2 = false;
		}
		i++;
		j--;
		if(!f1 && !f2)
			break;
	}
	if(c1 == 0)
		cout << c2 << endl;
	else if(c2 == 0)
		cout << c1 << endl;
	else if(c1 <= c2 && c1 != 0 && c2 != 0)
		cout << c1 << endl;
	else if(c2 < c1 && c1 != 0 && c2 != 0)
		cout << c2 << endl;
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int min1=100,n,m,qian,a[101];
int main()
{
	scanf("%d%d%d",&m,&n,&qian);
	for (int i=1;i<=m;i++)
	  scanf("%d",&a[i]);
	for (int i=n-1;i>=1;i--)
	  if (a[i]!=0&&a[i]<=qian)
	  {
	  	min1=n-i;
	  	break;
	  }
	for (int i=n+1;i<=m;i++)
	  if (a[i]!=0&&a[i]<=qian)
	  {
	  	min1=min(min1,i-n);
	  	break;
	  }
	printf("%d",min1*10);
	return 0;
}

#include<bits/stdc++.h>
using namespace std;

long long x,i,p,j,q,t,k[1000],m,mm,nn,n,y;
double xx,yy;
char l[3000][3000],ll[10000000];
int main()
{
    cin>>x>>p>>q;
    m=0;
    n=0;
    mm=0;
    nn=0;
    for(i=1; i<=x; i++)
        cin>>k[i];
    for(i=p+1; i<=x; i++)
    {
        m=m+10;
        if(k[i]<=q&&k[i]>0)
        {
            mm=1;
            break;
        }
    }
    for(i=p-1; i>0; i--)
    {
        n=n+10;
        if(k[i]<=q&&k[i]>0)
        {
            nn=1;
            break;
        }
    }
    if(mm==0)
        cout<<n<<endl;
    else if(nn==0)
        cout<<m<<endl;
    else
    {
        if(m>=n)
            cout<<n<<endl;
        else
            cout<<m<<endl;
    }

}

#include <iostream>

using namespace std;

int main()
{int n, m, k, a, c, b;
 cin >> n >> m >> k;
  b=0;
  c=0;
	for(int i=1;i<=n;i++)
	{cin >> a;
	     if (i<m&&a!=0&&k>=a)
	      b=(m-i)*10;
	     if(i>m&&a!=0&&k>=a)
	      {c=(i-m)*10;
	      break;}
	}
   if ((b>c&&c!=0)||(b==0))
	cout << c;
   else
    cout << b;
	return 0;
}

#include <iostream>

using namespace std;

int main()
{
	int n, m, k, a, rast, rast1;
	cin >> n;
	cin >> m;
	cin >> k;
	int *arr;
	arr = new int[n];
	if(n == 2)
	{
	    rast = 10;
	}
	else
	{
	    rast = (n - 1) * 10;
	    for (int i = 1; i <= n; i++)
	    {
    		cin >> a;
	    	if (a <= k && a!=0)
	    	{
        		rast1 = (i - m)*10;
	    		if (rast1 < 0)
	    		{
	    			rast1 = (m - i) * 10;
	    		}
	    		if (rast1 < rast)
	    		{
		    		rast = rast1;
	    		}
	    		if(rast == 10)
	    		{
	    		    i = n;
	    		}
	    	}
    	}
	}
	cout << rast;
	return 0;
}

#include <iostream>
#include <algorithm>
#include <cmath>
#include <string>

using namespace std;

#define then ;
#define cin(n); int n; cin>>n;
#define stop return 0;
//IgorI
//It is true or false
//Is it true or false?

int main()
{
     int n;
     int m;
     int k;

     cin>>n>>m>>k;
     m--;
     int a[1000];
     for(int i=0; i<n; i++)
       cin>>a[i];
     int ans1=99999,ans2=99999;
     for(int i=m+1; i<n; i++)
     {
          if((a[i]<=k)&&(a[i]>0))
          {
               ans1=(i-m)*10;
               break;
          }
     }
     for(int i=m-1; i>=0; i--)
     {
        if((a[i]<=k)&&(a[i]>0))
          {
               ans2=(m-i)*10;
               break;
          }
     }
     //cout<<ans1<<" "<<ans2<<" ";
     cout<<min(ans1,ans2);

}

#include<bits/stdc++.h>

using namespace std;

int main()
{
  int n,m,k,a,ans=1e9;cin>>n>>m>>k;

  for(int i = 1;i<=n;i++)
  {
    cin>>a;
    if(a<=k&&a>0)
    {
        ans=min(ans,abs(m-i)*10);

    }

  }
cout<<ans;

  return 0;

}

#include <iostream>
#include <math.h>
#include <stdlib.h>

using namespace std;

int main()
{
    int n,m,k;
    int i;
    cin >> n >> m >> k;
    int *Arr = (int *) malloc( n * sizeof(int));
    for(i=0 ; i<n ; i++)
    {
        cin >> Arr[i] ;
    }
    int diff;
    m--;
    int diff2;
    for(i=0 ; i<n ; i++)
    {
        if(Arr[i]!=0 && Arr[i]<=k)
        {
            if(diff)
            {
                if(i>m)
                        diff2 = i-m;
                    else
                        diff2 = m-i ;

                if(diff2 < diff)

                    diff = diff2;
            }
            else
            {
                if(i>m)
                    diff = i-m;
                else
                    diff = m-i;

            }

        }
    }
        cout << diff * 10;

        free(Arr);

        return 0;
    }

#include <stdio.h>
#include <iostream>
#include <math.h>

using namespace std;

int main()
{
	long long n,m,k,num,dis,max;
	//freopen("list.txt","r",stdin);
	cin>>n>>m>>k;
	dis=n;
	max=k;
	for (long long i=0;i<n;i++)
	{
		cin>>num;
		if (num!=0 && num<=max && abs(i+1-m)<dis)
			dis=abs(i+1-m);
	}

	cout<<dis*10<<"\n";
}

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>
#include <cmath>
#include <vector>
#include <string>
#include <set>
#include <algorithm>
#include <map>
#include <queue>
#include <clocale>
#include <bitset>
#include <memory.h>

using namespace std;

#pragma comment (linker, "/STACK:667177216")
#define ll long long
#define LL long long
#define ull unsigned long long
#define sc(a) scanf("%d",&a)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define mp make_pair
#define pb push_back
const ll mod = 1000000009;
#define INF (int)(2e9 + 1e8)
#define LINF (ll)(4e18)
#define forn(i,n) for(int (i) = 0;(i)<n;i++)
#define forit(mas) for(auto(it)=(mas).begin();(it)!=(mas).end();(it)++)

int main() {

#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	int n, m, k;
	cin >> n >> m >> k;
	vector<pair<int, int>>mas;
	for (int i = 1; i <= n; i++) {
		int a;
		cin >> a;
		if (a != 0) mas.pb(mp(abs(m - i)* 10,a));
	}
	sort(all(mas));
	for (int i = 0; i < mas.size(); i++) {
		if (mas[i].second <= k) {
			cout << mas[i].first << endl;
			return 0;
		}
	}
	return 0;
}

#include<iostream>
#include<string>
#include<map>
#include<algorithm>
using namespace std;
int main()
{
	int n, m, k;
	cin >> n >> m >> k;
	int z,house=n+m;
	for (int i = 1; i <= n; i++)
	{
		cin >> z;
		if (z != 0 && z <= k && abs(i  -m) < abs(house  - m))
			house = i;
	}
	cout << abs(house - m) * 10;
	return 0;
}

#include <bits/stdc++.h>
#define maxn 1007
#define ll long long int
#define _Goodbye_ return 0;
#define space(a,b) cout << a << " " << b << endl;
#define pb push_back
#define is insert
#define _BIGBANG_ int main
#define Friendly ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);

using namespace std;
int a[maxn] ;
_BIGBANG_(){
	Friendly
	int n , m , k ;
	cin >> n >> m >> k ;
	for ( int i = 1 ; i <= n ; i++ ){
		cin >> a[i] ;
	}
/*	if ( m == 1 ){
		for ( int i = 2 ; i <= n ; i++ ){
			if ( a[i] <= k && a[i] != 0 ){
				cout << ( i - 1 ) * 10 ;
				return 0 ;
			}
		}
	}
	else if ( m == n ){
		 for ( int i = n - 1 ; i >= 1 ; i-- ){
		 	if ( a[i] <= k && a[i] != 0 ){
		 		cout << ( m - i ) * 10 ;
		 		return 0 ;
			 }
		 }
	}
	else {  */
		int res = 0 , ces = 0 ;
		for ( int i = m - 1 ; i >= 1 ; i-- ){
			if ( a[i] <= k && a[i] != 0  ){
				res = i ;
				break ;
			}
		}
		for ( int i = m + 1 ; i <= n ; i++ ){
			if ( a[i] <= k && a[i] != 0 ){
				ces = i ;
				break ;
			}
		}
		if ( res == 0 ){
			cout << abs ( ces - m ) * 10 ;
		}
		else if ( ces == 0 ){
			cout << abs ( m - res ) * 10 ;
		}
		else{
//			cout << res << " " << ces << endl ;
			cout << min( abs( m - res ) , abs( ces - m ) ) * 10 ;
		}
//	}

	_Goodbye_
}

#include<bits/stdc++.h>
using namespace std;
int leftans=9999999,rightans=9999999,n,a,m,q;
int main()
{
	scanf("%d%d%d",&n,&m,&q);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a);
		if(i<m&&a<=q&&a)leftans=(m-i)*10;
		if(i>m&&a<=q&&a){rightans=(i-m)*10;break;}
	}
	printf("%d\n",min(leftans,rightans));
	return 0;
}

#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
using namespace std;
int arr[1000];
int main() {

	int n, m, k, distanceMinLeft = INT_MAX, distanceMinRight = 0, tempDistance = 0;
	cin >> n >> m >> k;

	for (int i = 0; i < n; i++)
	{
		int a;
		cin >> a;
		arr[i] = a;
	}

	for (int i = 0; i < m; i++)
	{
		if (arr[i] == 0)
			continue;
		if (k >= arr[i]) {
			for (int j = i; j < m-1; j++)
			{
				tempDistance += 10;
			}
			if (tempDistance < distanceMinLeft) {
				distanceMinLeft = tempDistance;
			}
		}
		tempDistance = 0;
	}
	for (int i = m; i < n; i++)
	{
		if (arr[i] == 0)
			continue;
		if (k >= arr[i]) {
			for (int j = m; j <= i; j++)
			{
				distanceMinRight += 10;
			}
			break;
		}
	}
	if (distanceMinLeft != 0 && distanceMinRight != 0) {
		cout << min(distanceMinLeft, distanceMinRight) << endl;
	}
	else if (distanceMinLeft != 0 && distanceMinRight == 0) {
		cout << distanceMinLeft << endl;
	}
	else {
		cout << distanceMinRight << endl;
	}

	//system("pause");
	return 0;
}

// Day 2.cpp : Этот файл содержит функцию "main". Здесь начинается и заканчивается выполнение программы.
//

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
	//reopen("input.txt", "r", stdin);
	// freopen("output.txt", "w", stdout);
	// 1 0 1 0 1 0
	// 0 1 1 0 1 0
	// 1 0 0 1 0 1
	int n, m, k;
	cin >> n >> m >> k;
	m--;
	int mn = 1e9;
	for (int i = 0; i < n; i++)
	{
		int temp;
		cin >> temp;
		if (temp == 0)
			continue;
		if (temp > k)
			continue;
		int dist = abs(i - m);
		mn = min(mn, dist);
	}
	cout << mn * 10 << endl;
	// n != 1 * 2 * 3 * 4 * ... * n;
}

// Запуск программы: CTRL+F5 или меню "Отладка" > "Запуск без отладки"
// Отладка программы: F5 или меню "Отладка" > "Запустить отладку"

// Советы по началу работы
//   1. В окне обозревателя решений можно добавлять файлы и управлять ими.
//   2. В окне Team Explorer можно подключиться к системе управления версиями.
//   3. В окне "Выходные данные" можно просматривать выходные данные сборки и другие сообщения.
//   4. В окне "Список ошибок" можно просматривать ошибки.
//   5. Последовательно выберите пункты меню "Проект" > "Добавить новый элемент", чтобы создать файлы кода, или "Проект" > "Добавить существующий элемент", чтобы добавить в проект существующие файлы кода.
//   6. Чтобы снова открыть этот проект позже, выберите пункты меню "Файл" > "Открыть" > "Проект" и выберите SLN-файл.

#include <bits/stdc++.h>

using namespace std;

int main()
{
	#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	#endif // ONLINE_JUDGE

	long long int n,m,k,i,a[500],flag = 0,flag1 = 0,pos,pos1;
	cin >> n >> m >> k;

	for(i = 0;i<n;i++)
	{
		cin >> a[i];
	}

	for(i = m;i<n;i++)
	{
		if(a[i]!=0 && a[i]<=k)
		{
			flag = 1;
			pos = i;
			break;
		}
	}

	for(i = m;i >=0;i--)
	{
		if(a[i]!=0 && a[i]<=k)
		{
			flag1 = 1;
			pos1 = i;
			break;
		}
	}

	if(flag != 1)
	{
		cout<<abs((m-pos1-1)*10);
	}
	else if(flag1 != 1)
	{
		cout<<abs((m-pos-1)*10);
	}
	else
	{

		if(abs(m-pos1-1) < abs(m-pos-1))
		{
			cout<<abs((m-pos1-1)*10);
		}
		else
		{
			cout<<abs((m-pos-1)*10);

		}
	}

}

#include<bits/stdc++.h>
using namespace std;
int p[100001];

int main()
{
	int n,m,k;
	cin>>n>>m>>k;
	int min=999;
	p[m]=0;
	for(int i=1;i<=n;++i)
	{
		cin>>p[i];
	}
	int dis=0;
	for(int i=1;i<=n;++i)
	{
		if(p[i]!=0&&p[i]<=k)
		{
			dis=abs(i-m)*10;
			if(dis<min)
			{
				min=dis;
			}
		}
	}
	cout<<min;
}

#include<bits/stdc++.h>

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, m, k, arr[100];
    cin >> n >> m >> k;
    for (int i = 0; i < n; i++)
        cin >> arr[i];
    m--;
    int mn = 2147483647;
    for (int i = m; i >= 0; i--)
        if (arr[i] > 0 && arr[i] <= k)
        {
            mn = min(mn, m - i);
            break;
        }
    for (int i = m; i < n; i++)
        if (arr[i] > 0 && arr[i] <= k)
        {
            mn = min(mn, i - m);
            break;
        }
    cout << mn * 10 << '\n';
    return 0;
}

#include <iostream>
using namespace std;
int main(){
	int n,m,p,*a;
	cin>>n>>m>>p;
	m--;
	a=new int [n];
	for(int i=0; i<n; i++) cin>>a[i];
	for(int i=1;;i++){
		if(m+i<n && a[m+i]!=0 && a[m+i]<=p ||m-i>=0 && a[m-i]!=0 && a[m-i]<=p){
			cout<<i*10;
			break;
		}
	}
}

#include <bits/stdc++.h>
using namespace std;

int main(){
    int n, m, k;
    cin >> n >> m >> k;
    m--;
    vector<int> a(n);
    for (int i = 0; i < n; i++)
        cin >> a[i];

    int res = 10000000;
    for (int i = n - 1; i > m; i--)
        if (a[i] != 0 && a[i] <= k)
            res = (i - m) * 10;

    for (int i = 0; i < m; i++)
        if (a[i] != 0 && a[i] <= k && res > (m - i) * 10)
            res = (m - i) * 10;

    cout << res;
    return 0;
}

#include <bits/stdc++.h>

#define ll long long
#define F first
#define S second
#define ever (;;)
#define all(x) x.begin(),x.end()
#define loop(i,o,n) for(int i=o;i<n;i++)
#define loop1(i,o,n) for(int i=o;i<=n;i++)
#define FixTo(x , y) cout.precision(y),cout << fixed << x
#define Life_Is_A_Game_All_You_Have_To_Do_Is_Know_How_To_Play_It ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);

using namespace std;

int main()
{
    int n,m,k;
    bool c=0,b=0;
    cin>>n>>m>>k;
    int a[n];
    for(int i=0;i<n;i++)
     cin>>a[i];

    m--;
    int s1=0,s2=0;
    for(int i=m-1;i>=0;i--)
    {
          s1++;
         if(a[i]<=k&&a[i]>0){
          c=1;
          break;
         }

    }
      for(int i=m+1;i<n;i++)
    {     s2++;
         if(a[i]<=k&&a[i]>0){
          b=1;
          break;
         }
    }

    if((c==1 && b==1 && s1<s2)||(c==1 && b==0))
     cout<<s1*10<<"\n";
    else
     cout<<s2*10<<"\n";

}

#include <iostream>

using namespace std;

#define MAXN 101

int n, m, k;
int cost[MAXN];

int main(){
	//freopen("input.txt", "rt", stdin);
	cin >> n >> m >> k;
	m--;
	for(int i = 0; i < n; i++){
		cin >> cost[i];
	}
	int Min = 1000000000;
	for(int i = m-1; i >= 0; i--){
		if(cost[i] != 0 && cost[i] <= k){
			Min = 10*(m-i);
			break;
		}
	}
	for(int i = m+1; i < n; i++){
		if(cost[i] != 0 && cost[i] <= k){
			if(Min > 10*(i-m)){
				Min = 10*(i-m);
			}
			break;
		}
	}

	cout << Min << endl;

	return 0;
}

#include <iostream>
#include <iomanip>
#include <cstdlib>

#include <cmath>
#include <cstring>
#include <cstdio>

int main()
{
	int n,m,k,i,j=1,cost,ans;

	scanf("%d %d %d",&n,&m,&k);
	int ara[n+1];
	memset(ara,0,sizeof(ara));
	for(i=1;i<=n;i++)
	{
		scanf("%d",&ara[i]);
	}
	cost=9999;

	for(i=m+1;i<=n;i++)
	{
		if(ara[i]<=k && ara[i]!=0)
		{
				cost=10*j;
				break;

		}
		j++;
	}
	j=1;
	int store=9999;
	for(i=m-1;i>=1;i--)
	{
		if(ara[i]<=k && ara[i]!=0)
		{
				store=10*j;
				break;
		}
		j++;
	}
	if(store<cost)
	{
		ans=store;
	}
	else
	{
		ans=cost;
	}
	printf("%d\n",ans);

	return 0;
	//main();
}

#include <iostream>

void main()
{
	int n,m,k;
	std::cin>>n>>m>>k;
	m--;

	int temp = 0, min = 10000;
	int value;

	for(int i = 0; i < n; i++)
	{
		std::cin>>temp;

		if(temp != 0)
		{
			if(temp <= k)
			{
				if(i < m)
					value = m - i;
				else
					value = i - m;
				min = std::min(min, value);
			}
		}
	}
	std::cout<<min * 10;
}

#include <iostream>

using namespace std;
int N,M,i,j,k,val,maxi,Vect[101],di,dj;

int main()
{
    cin>>N>>M>>k;
    for(i=1;i<=N;i++) cin>>Vect[i];
    i=M-1; j=M+1; di=10000; dj=10000;
    while(i>=1 && (Vect[i]==0 || Vect[i]>k)) i--;
    if(i>=1 && Vect[i]>0 && Vect[i]<=k) di=M-i;
    while(j<=N &&(Vect[j]==0 || Vect[j]>k)) j++;
    if(j<=N && Vect[j]>0 && Vect[j]<=k) dj=j-M;
    cout<<min(di*10,dj*10)<<'\n';
    return 0;
}

using namespace std;
#include <iostream>
#include <conio.h>

int main()
{
    int n,m,k,minim=100,v=100;
    cin>>n>>m>>k;
    int a[n+1];
    for(int i=1; i<=n; i++)
    {
        cin>>a[i];
    }
    for(int j=1; j<=n; j++)
    {
        if(a[j]>0)
        {
            if(a[j]<=k)
            {
                if(m-j>0)
                {
                    v=m-j;
                }
                else
                {
                    v=j-m;
                }
                if(v<minim)
                {
                    minim=v;
                }
            }
        }
    }
    minim=minim*10;
    cout<<minim;
    return 0;
}

#include<iostream>//CF796A
#include<cstdio>
#include<cstring>
#include<string>
#include<iomanip>
#include<algorithm>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<set>
using namespace std;
int a[200];
int main()
{
	int n,m,i,k,j,l,p;
	cin>>n>>m>>k;a[0]=a[n+1]=1000;l=p=0;
	for(i=1;i<=n;i++)cin>>a[i];
	for(i=m,j=m;i!=0||j!=n+1;)
	 {
	 	if(i>=1){i--;if(a[i]!=0&&a[i]<=k&&a[i]!=1000)l=i;}
	 	if(j<=n){j++;if(a[j]!=0&&a[j]<=k&&a[j]!=1000)p=j;}
	 	if(l!=0||p!=0)
	 	 if(a[l]<=a[p]){cout<<(m-l)*10<<endl;return 0;}
	 	 else{cout<<(p-m)*10<<endl;return 0;}
	 }
	 return 0;
}

#include <iostream>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <algorithm>

using namespace std;

#define ll long long

int main() {
	ll i, n, m, k, A[110];
	cin >> n >> m >> k;
	for (i=0;i<n;i++) {
		cin >> A[i];
	}
	ll ans;
	ll lans = 0, lpin = 0;
	for (ll j=m-1;j<n;j++) {
		if (A[j]<=k && A[j]!=0) {
			lpin = 1;
			break;
		}
		else lans++;
	}
	ll rans = 0, rpin = 0;
	for (ll j=m-1;j>=0;j--) {
		if (A[j]<=k && A[j]!=0) {
			rpin = 1;
			break;
		}
		else rans++;
	}
	if (lpin == 0) ans = rans;
	else if (rpin ==0) ans = lans;
	else ans = rans>lans?lans:rans;

	cout << ans*10 << endl;
	return 0;
}

#include <iostream>
#include <math.h>

using namespace std;

int main(int argc, char *argv[])
{
   int n, m, k;
   int a[100];
   int answer = 1000;

   cin >> n >> m >> k;
   for (int i = 0; i < n; ++i)
       cin >> a[i];

   for (int i = 0; i < n; ++i)
       if (a[i] && a[i] <= k)
           if (abs(i-m+1) < answer)
               answer = abs(i-m+1);

   cout << answer * 10;

   return 0;
}

#include<bits/stdc++.h>
using namespace std;
#define NN 200
int a[NN],b[NN];
int main(){
	int n,m,k,t=0,q=0,l=100;
	scanf("%d%d%d",&n,&m,&k);
	for(int i=1;i<=n;i++){
		scanf("%d",a+i);
		if(a[i]>0 && a[i]<=k){
			q=abs(m-i);
			if(q<l) l=q;
		}
	}
	printf("%d",l*10);
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int val[101],id,mon,n;
bool b[101];
int main()
{
    cin>>n>>id>>mon;
    for(int i=1;i<=n;i++)
    {
        cin>>val[i];
        if(!val[i])
        {
            b[i]=1;
        }
    }
    int l=id,r=id;
    while(1)
    {
        if(l<=0)
        {
            l=1;
        }
        if(r>n)
        {
            r=n;
        }
        if(b[l]||val[l]>mon)
        {
            l--;
        }
        else
        {
            cout<<(id-l)*10<<endl;
            return 0;
        }
        if(b[r]||val[r]>mon)
        {
            r++;
        }
        else
        {
            cout<<(r-id)*10;
            return 0;
        }
    }
    return 0;
}

/*Saidur Rahman Sajol:The Freak*/
  /*Dept. of CSE,IUBAT(162)*/
/*---------------------------*/

#include <bits/stdc++.h>
using namespace std;

#define PI 2*acos(0.0)
#define l long long
#define ll long long
#define ul unsigned long
#define ull unsigned long long

ull minimum(ull a,ull b){
  return (a<b)?a:b;
}
ull maximum(ull a,ull b){
  return (a>b)?a:b;
}
ull great(ull a,ull b){
	if(b==0) return a;
  return great(b,a%b);
}

int main(){
	int n,m,k;
	scanf("%d %d %d",&n,&m,&k);
	int s[n];
	for(int i=0;i<n;i++){
		scanf("%d",&s[i]);
	}
	vector<int>pb;
	vector<int>ps;
	for(int i=0;i<m;i++){
		if(s[i]!=0 && s[i]<=k){
			pb.push_back(i+1);
		}
	}
	for(int i=m;i<n;i++){
		if(s[i]!=0 && s[i]<=k){
			ps.push_back(i+1);
		}
	}
	int seize=pb.size();
	int ana=ps.size();
	if(seize<=0 && ana>0){
		int freak=ps[0];
		int node=abs(freak-m);
		ll weird=10LL*node;
		printf("%lld\n",weird);
	}
	else if(ana<=0 && seize>0){
		int freak=pb[seize-1];
		int node=abs(freak-m);
		ll weird=10LL*node;
		printf("%lld\n",weird);
	}
	else if(ana>0 && seize>0){
		int freak=pb[seize-1];
		int freak1=ps[0];
		int diff1=abs(freak-m);
		int diff2=abs(freak1-m);
//		cout<<diff1<<" "<<diff2<<endl;
		int nude=minimum(diff1,diff2);
	//	int node=abs(nude-m);
		ll weird=10LL*nude;
		printf("%lld\n",weird);
	}
	else puts("0");

	return 0;
}

#include <iostream>
#include <string.h>
#include <set>
#include <vector>
#include <queue>
#include <cmath>
#include <math.h>
#include <algorithm>
#include <map>
#include <stack>
#include <iomanip>
#include <functional>
#include <limits.h>
using namespace std;
#define ll long long int
#define rep(i,n) for(ll i=0;i<n;i++)
#define rep2(i,n) for(ll i=1;i<n;i++)
#define N 100000
//done?????
int main()
{
    ll n,m,k,c=INT_MAX;
    cin>>n>>m>>k;
    ll a[n+1];
    rep2(i, n+1)
    {
        cin>>a[i];
        if(a[i]!=0&&a[i]<=k)
        {
            c=min(c,abs(i-m));
        }
    }
    cout<<10*c;

}

#include <iostream>
#include <stdlib.h>

using namespace std;

void main() {
	int n, m, k, rast, minR;
	cin >> n >> m >> k;
	int *a = new int [n+1];
	minR = 10 * n;
	for (int i = 1; i <= n; i++)
	{
		cin >> a[i];
		if (i < m && k >= a[i] && a[i] != 0)
		{
			rast = 10 * (m - i);
			if (rast < minR) minR = rast;
		}
		else if (i > m && k >= a[i] && a[i] != 0)
		{
			rast =  10 * (i - m);
			if (rast < minR) minR = rast;
		}
	}
	cout << minR;
	cin >> n;
}

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    int n , m , k , arr[110] , md=10000;

    cin>>n>>m>>k;

    for(int i = 0 ; i < n ; i++)
    {
        cin>>arr[i];

    }

    for(int i =0 ; i <n ; i++)
    {
        if(arr[i]<=k && arr[i]!=0)
            {if( abs(i-(m-1))*10 < md)
              md=abs(i-(m-1))*10;
            }
    }

    cout<<md<<endl;

    return 0;
}

/* (: Sreejith Codes :) */

#include    <bits/stdc++.h>

#define 	ll 	long long
#define 	ld 	long double
#define 	pb 	push_back
#define 	ff 	first
#define 	ss 	second
#define 	mp 	make_pair
#define 	pi 	3.141592653589793
#define 	ios ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;

int main()
{
	ios;
	ll n,k,r,c=0,a=1000000,b=1000000000,bb;
	cin>>n>>k>>r;
	vector < ll > v;
	v.pb(0);
	for(ll i = 0 ; i < n ; i++ )
	{
		cin>>bb;
		v.pb(bb);
	}
	for(ll i=k-1 ; i >=1 ; i--)
	{
		c++;
		if(v[i]!=0)
		{
			if(v[i]<=r)
			{
				a=c;
				break;
			}

		}
	}

	c=0;
	for(ll i=k+1 ; i <= n ; i++)
	{
		c++;
		if(v[i]!=0)
		{
			if(v[i]<=r)
			{
				b=c;
				break;
			}
		}
	}

	c=min(a,b);
	c*=10;
	cout<<c;

	return 0;
}

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
   int n , m , k , min=100 ;
   int arr [101];
   cin >> n >> m >> k ;

   for (int i = 0 ; i< n ; i ++)
   {
       cin >> arr[i];
   }

   for(int i = 1 ; i <= n ; i ++)
   {
       if(arr[i-1]!=0&&arr[i-1]<=k)
       {

           if(min > abs(i-m))
           {
               min = abs(i-m);
           }

       }
   }

   cout << min*10<<endl;
    return 0;
}

//author:satwik_bhv1
#include<bits/stdc++.h>
//datatypes
#define ll long long
#define ld long double
//loops
#define fr(i,z,n) for(ll i=z;i<n;i++)
#define br(i,z,n) for(ll i=z;i>n;i--)
//operations
#define mp  make_pair
#define ff  first
#define ss  second
#define pub push_back
#define puf push_front
#define pob pop_back
#define pof pop_front
//deque
#define dki deque <ll>
#define dkc deque <char>
//map
#define mi map<ll, ll>
#define mf map<ld, ld>
//vectors
#define vi vector<ll>
#define vc vector<char>
#define vpi vector< pair <ll,ll> >
#define vpc vector<pair <char,char> >
#define vpic vector<pair <ll,char> >
#define vpci vector<pair <char,ll> >
//constants
#define pi 3.1415926535897932384626
#define mod 998244353
/*notes
    pow function should not be used use power function
    range of longlong=(-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 )
    INT_MAX = 2147483647(aprox 2*10^10)
    INT_MIN = -2147483648
    LLONG_MAX = 9223372036854775807
    LLONG_MIN = -9223372036854775808
    MST -> kruskal(DSU)
    sssp -> Dijkstras
    apsp -> Floydwarshall
    __gcd is the function in built for hcf

*/
//start
using namespace std;
//functions
void fast() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); }
bool sortbysec(const pair<ll, ll>& a, const pair<ll, ll>& b) { return (a.second < b.second); }
ll vis[100001],dis[100001];
vi ar[100001];
ll len;
void solve()
{
    ll n,m,k;
    cin>>n>>m>>k;
    vi v(n);
    fr(i,0,n)
    {
        cin>>v[i];
    }
    ll ans=n;
    ll ind=-1;
    fr(i,0,n)
    {
        if(v[i]!=0&&v[i]<=k)
        {
            if(ans>abs(i-(m-1)))
            {
                ans=abs(i-m+1);
                ind=i;
                //cout<<i<<" ";
            }
        }
    }
    cout<<ans*10;
}
int main()
{
    fast();
    ll t;
    //cin>>t;
    t=1;
    while(t--)
    {
        solve();
    }
}

#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>

using namespace std;

#define pb push_back
#define fast_cin() ios_base::sync_with_stdio(false)

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

const int N = 1e5 + 5;

int main()
{
	int n, m, k;
	cin >> n >> m >> k;
	int ans = N;
	for (int i = 1; i <= n; ++i)
	{
		int a;
		cin >> a;
		if (a > 0 and a <= k)
			ans = min(ans, 10 * abs(i - m));
	}
	cout << ans;
}

#include <bits/stdc++.h>
using namespace std;

signed main() {

	int n, m, k;
	cin >> n >> m >> k;

	int a[n + 1];
	for(int i = 1; i <= n; i++)
		cin >> a[i];

	int l = m - 1, r = m + 1;

	bool left = 0;

	while(l >= 1 or r <= n)
	{
		if(l >= 1 and a[l] <= k and  a[l] != 0)
		{
			left = 1;
			break;
		}

		if(r <= n and a[r] <= k  and a[r] != 0)
		{
			break;
		}

		l--;
		r++;
	}

	if(left)
		cout << (m - l) * 10;
	else
		cout << (r - m) * 10;

	return 0;
}

#include<iostream>
#include<bits/stdc++.h>
#define ll long long int

using namespace std;

int main(){
    ll n,m,k,i,val;
    cin>>n>>m>>k;
    ll mn=INT_MAX;
    for(i=1;i<=n;i++){
        cin>>val;
        if(val>0 && val<=k && i!=m)
         mn=min(mn,abs(i-m));
    }

    cout<<mn*10<<endl;
}

#include<iostream>
using namespace std;
int n, m, k, a[101], ans;
main ()
{
     cin>>n>>m>>k;
     for (int i=1; i<=n; i++)
     cin>>a[i];
     for (int i=m-1; i>=1; i--)
     if (a[i]<=k && a[i]!=0) {ans=m-i; break;}
     for (int i=m+1; i<=n; i++)
     if (a[i]<=k && a[i]!=0) {if (ans>i-m || ans==0) ans=i-m; break;}
     cout<<ans*10<<endl;
     //system ("pause");
}

#include<iostream>
using namespace std ;
int main ()
{

int x,y,z,a,small(10000);
cin>>x>>y>>z;
int *arr1 = new int [x];
for (int i=0 ;i<x;i++)
cin>>arr1[i];
// check for 0
int v(0),c(0);
for (int i=0;i<x;i++)
{
if(c==arr1[i])
	v++;
}
if(v==x)
	cout<<'0'<<endl;
else {
	for(int i=0;i<x;i++)
	{
		int d(0);
if (z>=arr1[i]&&arr1[i]!=0)
{
	a=i+1;
	if (y>a)
d=y-a;
	else
		d=a-y;
	if (small>d)
		small =d;
}

	}
	cout<<small*10<<endl;

     }

	return 0 ;
}

#include<iostream>
using namespace std;
int n,m,k,a[105],dem,dem1,dem2;
main(){
	cin>>n>>m>>k;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	for(int i=m-1;i>=0;i--){
		if(a[i]<=k&&a[i]!=0){
			dem1=(m-i)*10;
			break;
		}
	}
	for(int i=m+1;i<=n;i++){
		if(a[i]<=k&&a[i]!=0){
			dem2=(i-m)*10;
			break;
		}
	}
	if(dem1==0) dem=dem2;
	else if(dem2==0) dem=dem1;
	else{
		if(dem1>dem2) dem=dem2;
		else dem=dem1;
	}
	cout<<dem;
}

#include<iostream>
#include<string>
using namespace std;

int main()
{
	int houses_number, girlfriends_house, zeins_amount, house_price;
	cin >> houses_number >> girlfriends_house >> zeins_amount;
	double * prices_arr = new double[houses_number];
	int min_distance = 1000000;
	int suitable_price_index;
	int * indexes_arr = new int[houses_number];
	int indexes_arr_countrer = 0;
	int girlfriends_house_index = girlfriends_house - 1;

	for (int i = 0; i < houses_number; i++)
	{
		cin >> house_price;
		prices_arr[i] = house_price;
	}

	suitable_price_index = 1000000;
	int suitable_house_index = 0;

	for (int i = 0; i < houses_number; i++)
	{
		if (prices_arr[i] <= zeins_amount && prices_arr[i] > 0)
		{
			suitable_price_index = prices_arr[i];
			indexes_arr[indexes_arr_countrer] = i;
			indexes_arr_countrer++;
		}
	}

	for (int i = 0; i < indexes_arr_countrer; i++)
	{
		suitable_house_index = girlfriends_house_index - indexes_arr[i];
		if (abs(suitable_house_index) < min_distance)
		{
			min_distance = abs(suitable_house_index);
		}
	}

	cout << min_distance * 10 << endl;

	return 0;
}

#include <iostream>
#include <cstdio>
using namespace std;
int a[10000];
int main()
{
	int n,m,k;
	cin>>n>>m>>k;

	int i;
	for(i = 1;i<=n;i++)
		scanf("%d",&a[i]);
	int flag = 0;
	int j = m;
	for(i = m+1;;i++)
	{
		if(j<1&&i>n)
			break;
		j--;
		if(j>0)
			if(a[j]<=k&&a[j]!=0)
			{
				flag = m-j;
				break;
			}
		if(a[i]<=k&&a[i]!=0&&flag==0)
		{
			flag = i-m;
			break;
		}
	}
	cout<<flag*10<<endl;
	return 0;
}

#include <iostream>

#include<algorithm>

#include<math.h>

using namespace std;

int n, m, k, a,i, ans=INT_MAX;

int main()
{
    cin>>n>>m>>k;
    for(i=1;i<=n;i++)
    {
        cin>>a;
        if(a>0 && a<=k)
        {
            if(abs(m-i)<ans)
            {
                ans=abs(i-m);
            }
        }

    }
    cout<<ans*10;

return 0;
}

#include <bits/stdc++.h>
#include<math.h>
#define pi 2.0*acos(0.0)
#define MAX 100005
typedef long long ll;
using namespace std;

int main()
{
    ll a[MAX],i,m,n,k,count1,count2;

    count1=0;
    count2=0;
    cin>>n>>m>>k;
    for(i=1;i<=n;i++)
        cin>>a[i];
    for(i=m;i<=n;i++)
        {
            if(a[i]<=k && a[i]!=0)
                {
                    break;
                }

            if(a[i]>k || a[i]==0)
                {
                    count1=count1+10;
                    if(i==(n))
                        count1=MAX;
                }

        }
    if(m==1)
        {
            cout<<count1;
            return 0;
        }
    for(i=m;i>=1;i--)
        {
            if(a[i]<=k && a[i]!=0)
                    break;
            if(a[i]>k || a[i]==0)
                {
                    count2=count2+10;
                    if(i==1)
                        count2=MAX;
                }

        }
    if(m==n)
        {
            cout<<count2;
            return 0;
        }
    if(count1<count2)
        cout<<count1;
    else if(count1>count2)
        cout<<count2;
    else
        cout<<count1;
    return 0;
}

#include <iostream>
#include <vector>
using namespace std;

int main()
{
    int n, m, d;
    vector<int> prices;
    cin >> n >> m >> d;
    int p;
    for(int i = 0; i < n; i++){cin >> p; prices.push_back(p);}
    int l = 100001;
    for(int i = 0; i < n; i++)
    {
        if(prices[i] != 0 && prices[i] <= d)
        {
            l = min(l, abs((i + 1) - m));
        }
    }
    cout << (l) * 10;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    long long x,y,z;
    cin>>x>>y>>z;
    long long a[x],b=0,c=0;
    for(int i=0;i<x;i++){
        cin>>a[i];
    }
    bool f=1;
    for(int i=y-1;i<x;i++){
        if(a[i]==0){b+=10;continue;}
        else if(z>=a[i]){f=0;break;}
        else{b+=10;}
    }
    bool d=1;
    for(int i=y-1;i>=0;i--){
        if(a[i]==0){c+=10;continue;}
        else if(z>=a[i]){d=0;break;}
        else{c+=10;}
    }
    if(!d&&!f){cout<<min(c,b)<<endl;return 0;}
    else if(!d&&f){cout<<c<<endl;}
    else{cout<<b<<endl;}
    return 0;
}

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
    int n,m,k,i;
    int dis[101];
    cin>>n>>m>>k;
    for(i=1;i<=n;i++)
        cin>>dis[i];
    int minn=101;
    for(i=1;i<=n;i++){
        if(dis[i]<=k&&dis[i]){
            if(fabs(i-m)<minn)
                minn=abs(i-m);
        }
    }
    cout<<(minn)*10<<endl;
    return 0;
}

#include<bits/stdc++.h>

using namespace std;
int a[1500];
int b[1500];
int main()
{
    int n,m,r,mn=10000,mx=0,K=0,ans=9999;
    cin>>n>>m>>r;
    m--;
    for (int i=0;i<n;i++)
    {
        cin>>a[i];
    }
    for (int i=m+1;i<n;i++)
    {
        if (r>=a[i]&&a[i])
            ans=min(ans,i-m);
    }
    for (int i=m-1;i>=0;i--)
    {
        if (r>=a[i]&&a[i])
            ans=min(ans,m-i);
    }
    cout<<ans*10<<endl;
    return 0;
}

#include <iostream>
#include <stdlib.h>
using namespace std;

int main()
{
    int n=0,m=0,k=0;
    int a[101];
    int dis=100,tem=0;
    cin >> n >> m >> k;
    for(int i=0;i<n;i++){cin >> a[i];}
    m-=1;
    for(int i=0;i<n;i++){
        if(a[i]!=0 && k>= a[i]){
            tem = abs(i-m);
            if(tem<dis){
                    dis=tem;}
        }
    }
    cout << dis*10;
    //cout << "Hello world!" << endl;
    return 0;
}

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
    int n, m, k;
    cin >> n >> m >> k;
    vector<int> A(n);
    for (auto &a : A)
        cin >> a;

    int ans = 105;
    // ignore houses
    for (int i = 0; i < n; i++)
        if (A[i] > k)
            A[i] = 0;
    // houses to the right
    for (int d = 0, i = m - 1; i < n; i++, d++) {
        if (A[i] > 0) {
            ans = d;
            break;
        }
    }
    // houses to the left
    for (int d = 0, i = m - 1; i >= 0; i--, d++) {
        if (A[i] > 0) {
            ans = min(ans, d);
            break;
        }
    }
    cout << ans * 10;

    return 0;
}

#include<iostream>
#include<string.h>
using namespace std;
int main()
{
	int n,m,k,a[1000],mina=0,minb=0;
	cin >> n>>m>>k;
	for (int i = 1; i <= n; i++)
	{
		cin >> a[i];
	}
	int flaga = 0, flagb = 0;

	for (int i = m+1; i <= n; i++)
	{
		mina += 10;
		if (a[i] <= k && a[i]!=0)
		{
			flaga = 1;
			break;
		}
	}

	for (int i = m-1; i > 0; i--)
	{
		minb += 10;
		if (a[i] <= k && a[i] != 0)
		{
			flagb = 1;
			break;
		}

	}
	if (flaga == 0)
	{
		mina = 0;
	}

	if (flagb == 0)
	{
		minb = 0;
	}
	//cout << mina << endl;
	//cout << minb <<endl;

	if (mina > 0 && minb == 0) { cout << mina; goto end; }
	if (minb > 0 && mina == 0) { cout << minb; goto end; }
	mina >= minb ? cout << minb : cout << mina;
	end:
	//system("pause");
	return 0;
}

//gcc 5.4.0

#include  <stdio.h>
#include <iostream>
#include <stdlib.h>
#include <algorithm>
#include <vector>

using namespace std;

int main()
{
	string str;
	int n, m, d, k,b, rub, res, mm;
	vector<int> a;

	cin >> n >> mm >> k;

m=mm-1;
	for(int i=0; i< n; i++)
	{
		cin >> rub;

		a.push_back(rub);

	}

	int i = m-1;
	int j = m+1;
	while(1)
	{
		if(i >=0 && a[i] > 0 && a[i] <= k)
		{
			res = (m-i)*10;
			break;
		}
		if(j < n && a[j] > 0 && a[j] <= k)
		{
			res = (-m+j)*10;
			break;
		}
		i--;
		j++;

	}
cout << res;

getchar();
getchar();
	return 0;
}

#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define reg register
#define in cin>>
#define out cout<<
#define end return 0
#define ios ios_base::sync_with_stdio(false)
using namespace std;
int main(){
    ios;
    reg int n,m,k,ans=2147483647;
    in n>>m>>k;
    int a[n];
    for(reg int i=0;i<n;i++){
    	in a[i];
    	if(k<a[i])a[i]=0;
    	if(a[i]!=0){
			a[i]=10*abs(i+1-m);
			if(a[i]<ans)ans=a[i];
		}
    }
    out ans;
    end;
}

#include <iostream>
#include <string>
#include <cstring>
#include <cctype>

using namespace std;

int main() {
	int n, m, k;
	cin >> n >> m >> k;

	int *house_price = new int[n];

	for (int i = 0; i < n; i++) {
		cin >> house_price[i];
	}

	bool*available = new bool[n] {0};
	int *distance_of_house = new int[n];
	int min_distance=n;

	for (int i = 0; i < n; i++) {
		if (house_price[i] != 0) {
			available[i] = true;
		}
	}

	for (int i = 0; i < n; i++) {
		if (available[i]==true && house_price[i]<=k) {
			distance_of_house[i] = abs((m - 1) - i);
		}
	}

	for (int i = 0; i < n; i++) {
		if (distance_of_house[i] > 0) {
			if (distance_of_house[i] < min_distance)
				min_distance = distance_of_house[i];
		}
	}

	cout << min_distance * 10 << endl;

	//system("pause");
	return 0;
}

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb push_back

int main()
{
    ll i, n, m, k, a;
    vector < ll > v, v2;
    cin >> n >> m >> k;
    m--;
    for(i = 0; i < n; i++)
    {
        cin >> a;
        v.pb(a);
    }
    ll ans = 0, mn = 0, check = 0;
    for(i = m - 1; i >= 0; i--){
        if(v[i] <= k && v[i] != 0){
            mn += 10;
            check = 1;
            break;
        }
        else
            mn += 10;
    }
    if(check == 1)
        ans = mn;
    check = 0;
    mn = 0;
    //cout << m + 1 << endl;
    for(i = m + 1; i < n; i++){
        if(v[i] <= k && v[i] != 0){
            mn += 10;
            check = 1;
            break;
        }
        else
            mn += 10;
    }
    if(check == 0)
        mn = 0;
    //cout << ans << " " << mn << endl;
    if(ans != 0 && mn != 0)
        cout << min(ans, mn) << endl;
    else
        cout << max(ans, mn) << endl;

    return 0;
}

#include <iostream>
#define FOR(i,j,k); for(int i = j; i < k; ++i)
using namespace std;
long long int houses[10000];

void initialize(){
	FOR(i, 0, 10000){
		houses[i] = 0;
	}
}

int main(){
	int n, m, k;
	initialize();
	cin >> n >> m >> k;
	FOR(i, 1, n+1){
		cin >> houses[i];
	}
	int distancia = 0;
	int l = 0, r = 0;
	l = m - 1;
	r = m + 1;
	while (l >= 1 || r <= n){
		distancia += 10;
		if ((houses[l] != 0 && houses[l] <= k) || (houses[r] != 0 && houses[r] <= k)){
			cout << distancia << endl;
			break;
		}
		else{
			l -= 1;
			r += 1;
		}
	}
	return 0;
}

#include<bits/stdc++.h>

using namespace std;

int main()
{
	int m,n,k;
	cin>>n>>m>>k;
	vector<int>v(n);
	int finalpos,minimo = INT_MAX;
	for(int i = 0;i<n;i++)
	{
		cin>>v[i];
		if(v[i] != 0 && k >= v[i])
		{
			if(abs((i+1)-m) < minimo)
			{
				minimo = abs((i+1)-m);
				finalpos = i;
			}
		}
	}
	cout<<(minimo)*10;

}

#include<bits/stdc++.h>
typedef long long ll;
#define IOS ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
using namespace std;
int32_t main()
{
  IOS;
  int n,m,k;
  int minL,minR;
  cin>>n>>m>>k;
  int a[n+1];
  for(int i=1;i<=n;i++){
    cin>>a[i];
  }
  for(int i=m+1;i<=n;i++){
    if(a[i]<=k and a[i]!=0){
      minL=abs(i-m);
      break;
    }
  }
  for (int i = m-1; i >=0 ; --i)
  {
    if(a[i]<=k and a[i]!=0){
      minR=abs(i-m);
      break;
    }
  }
  (minR>minL)?cout<<(minL*10):cout<<(minR*10);

}

#include <iostream>
#include <cmath>
using namespace std;
int main(){
	int n,m,w,p,minp=1000000000;
	int a[102];
	cin>>n>>m>>w;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		if(a[i]!=0 && a[i]<=w ){
			p=abs(i-m)*10;
			if(p<minp)
				minp=p;
		}
	}
	cout<<minp;
}

#include<bits/stdc++.h>
using namespace std;
int arr[105];
vector<int>s;
int main(void)
{
    int n,m,k;
    scanf("%d %d %d",&n,&m,&k);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&arr[i]);
        if(arr[i]<=k && arr[i]!=0)
            s.push_back(abs(i-m));
    }
    sort(s.begin(),s.end());
    printf("%d\n",s[0]*10);
    return 0;
}

#include<iostream>
using namespace std;
int main(){

	int n,h,am,sum1=0,sum2=0;
	int array[103];
	cin>>n>>h>>am;
	for (int i = 0 ; i < n ;i++){
		cin>>array[i];
	}
	int flag1 = 1;
	for (int i = h-1 ;i < n ; i++){
		if (array[i]<=am && array[i]!=0){
			flag1 = 0;
			break;
		}
		else {

		sum1+= 10;
	}
	}
	int flag2 = 1;
	for (int i = h-1 ;i >= 0  ;i -- ){
		if (array[i]<=am && array[i]!=0){
			flag2 = 0;
			break;

		}
		else {
		sum2+=10;
	}
	}
   if (sum1<=sum2){
   	if (flag1==0)cout<<sum1<<"\n";
   	else cout<<sum2;
   }
   else  if (sum2<sum1){
   	if (flag2==0)cout<<sum2<<"\n";
   	else cout<<sum1;
   }

}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,p,k;
    cin >> n >> p >> k;
    --p;

    vector<int> a(n);
    for(auto& e:a) cin >> e;

    int i{p},j{p};
    while((a[i]>k||!a[i])&&--i>=0);
    while((a[j]>k||!a[j])&&++j<n);

    if(i==-1)
        cout << (j-p)*10;
    else if(j==n)
        cout << (p-i)*10;
    else
        cout << min(j-p,p-i)*10;
}

#include <iostream>
using namespace std;
int main()
{
    int n,m,k;
    cin >> n >> m >> k;
    int a[n];
    for (int i=0; i<n ;i++)
        cin >> a[i];
    int found = 1;
    int tr=0,i=1,j=1;
    while (found == 1)
    {
        if (tr%2==0)
        {
            if ((m-1+i)<n)
            {
                if (a[m-1+i]!=0)
                {
                    if (a[m-1+i]<=k)
                    {
                        cout << 10*i;
                        found = 0;

                    }
                }
            }
            else if ((m-1-j)<0)
                break;

        i++;
        }
        if (tr%2!=0)
        {
            if ((m-1-j)>=0)
            {
                if (a[m-1-j]!=0)
                {
                    if (a[m-1-j]<=k)
                    {
                        cout << 10*j;
                        found = 0;

                    }
                }
            }
            else if ((m-1+i)>n)
            break;

        j++;
        }
        tr++;
    }

}

#include<bits/stdc++.h>
#define ll int long long
using namespace std;
int main()
{
   int n,m,k,l=-1,r=-1;
   cin>>n>>m>>k;
   int a[n+1];
   for(int i=1;i<=n;i++)cin>>a[i];
   for(int i=m-1;i>0;i--){
      if(k>=a[i]&&a[i]!=0){l=i;break;}
   }
   for(int i=m+1;i<=n;i++){
      if(k>=a[i]&&a[i]!=0){r=i;break;}
   }
   if(l==-1||r==-1){cout<<10*abs(m-max(l,r));return 0;}
   cout<<10*min(abs(m-l),abs(m-r));
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,m,k;
    cin>>n>>m>>k;
    int a[n];
    int i;
    for(i=0;i<n;i++)
    {
        cin>>a[i];
    }
    m--;
    int j;
    i=m-1;
    j=m+1;
    int ans;
    while(1)
    {
        //cout<<i<<" "<<j<<" "<<n-1<<endl;
        if(i<0)
            i=0;
        if(j>n-1)
            j=n-1;
        if(a[i]&&a[j])
        {
            if(a[i]<=k&&a[j]<=k)
            {
              if(a[i]<a[j])
                    {
                        ans=i;
                        break;
                    }
              else
                {
                    ans=j;
                    break;
                }
            }
            else if(a[i]<=k)
            {
                ans=i;
                break;
            }
            else if(a[j]<=k)
            {
                ans=j;
                break;
            }
        }
        else if(a[i]&&a[i]<=k)
        {
            ans=i;
            break;
        }
        else if(a[j]&&a[j]<=k)
        {
            //cout<<"P"<<" ";
            ans=j;
            break;
        }

        {
            i--;
            j++;
        }
    }
    //cout<<ans<<" ";
    int x=(abs(ans-m))*10;
    cout<<x;
}

#include<iostream>
#include<cmath>

using namespace std;
int main()
{
    int n,m,j=0,mini,k;
    cin>>n>>m>>k;
    int a[101];
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
        if(a[i]<=k && a[i]!=0)
        {
            a[j]=(m-1)-i;
            if(a[j]<0)
            {
                a[j]=-a[j];
            }
            j++;
        }
    }
    mini=a[0];
    for(int i=1;i<j;i++)
    {
        if(a[i]<mini)
        {
            mini=a[i];
        }
    }
    cout<<10*mini<<endl;
    return 0;
}

#include <iostream>
#include <cmath>

using namespace std;

int main(){
	int q, n, m, k, t, s;
	s = 100;
	cin >> n >> m >> k;
	for (int i = 0; i < n; ++i) {
		cin >> q;
		if (q && q <= k) {
			t = abs(i - m + 1);
			if (t < s) {
				s = t;
			}
		}
	}
	cout << s * 10;
	return 0;
}

#include<bits/stdc++.h>
using namespace std;

int main()
{

	long n,i,m,k,lead=INT_MAX,cnt=0;
	cin>>n>>m>>k;
	m--;
	long a[n];
	for(i=0;i<n;i++)
	    cin>>a[i];
	for(i=m;i<n;i++)
	    {
	        //cout<<a[i]<<" ";
	        if(a[i]<=k && a[i]!=0)
	        {
	            cnt=a[i];
	            //cout<<cnt<<endl;
	            lead=(i-m);
	            break;
	        }
	    }
	    for(i=m-1;i>=0;i--)
	    {
	        //cout<<a[i]<<" ";
	        if(a[i]<=k && (m-i)<lead && a[i]!=0)
	        {
	            cnt=a[i];
	            //cout<<cnt<<endl;
	            lead=m-i;
	            break;
	        }
	    }
	    cout<<lead*10;
}

// by tmt514
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <string>
#include <vector>
#define SZ(x) ((int)(x).size())
#define FOR(it, c) for(__typeof((c).begin()) it = (c).begin(); it != (c).end(); ++it)
using namespace std;
typedef long long LL;

int a[105];
int main(void) {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);
  m -= 1;
  for(int i=0;i<n;i++) scanf("%d", &a[i]);
  for(int i=1;i<n;i++) {
    if((m-i>=0 && a[m-i] > 0 && a[m-i] <= k) ||
       (m+i<n && a[m+i] > 0 && a[m+i] <= k)) {
      printf("%d\n", i*10);
      return 0;
    }
  }
  return 0;
}

#include <stdio.h>
#include <iostream>
#include<vector>
using namespace std;

int main()
{
	int  n, m, k, d1 = 9999999999, d2 = 9999999999;
	vector <int> a;
	cin >> n >> m >> k;

	for (int i = 0; i < n; i++)
	{
		int b;
		cin >> b;
		a.push_back(b);
	}

	if (m>1)
	for (int j = 1; m - j - 1 > -1; j++)
	{
		if (a[m - j - 1] != 0 && (a[m - j - 1] < k || a[m - j - 1] == k))
		{
			d1 = 10 * j;
			break;
		}
	}

	if (m<n)
	for (int j = 1; m + j-1 < n; j++)
	{
		if (a[m + j - 1] != 0 && (a[m + j - 1] < k || a[m + j - 1] == k))
		{
			d2 = 10 * j;
			break;
		}

	}

	if (d1>d2)
		cout << d2;
	else
		cout << d1;

	return 0;

}

#include <bits/stdc++.h>
using namespace std;
int n, m, k, a[10000];
int main() {
	cin >> n >> m >> k;
	int ans = n + 1;
	m--;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
		if (a[i] != 0 && a[i] <= k) {
			ans = min(ans, abs(m - i));
		}
	}
	cout << ans * 10 << endl;
}

#include<iostream>
#include<algorithm>
using namespace std;
int main() {
	int n, m, k, a[100];
	cin >> n >> m >> k;
	for (int i = 0; i < n; ++i)
		cin >> a[i];
	/////////////////////////////
	int r = 100, l = 100;
	for(int i=m;i<n;++i)
		if (a[i] <= k && a[i] != 0) {
			r = i - m + 1;
			break;
		}
	for(int i=m-2;i>=0;--i)
		if (a[i] <= k && a[i] != 0) {
			l = m - i - 1;
			break;
		}
	cout << min(l, r) * 10;
	return 0;
}

#include<bits/stdc++.h>
using namespace std;

int main()
{
    int n,m,k;
    int arr[10000];
    cin>>n>>m>>k;
    for(int i=1;i<=n;i++)
    {
        cin>>arr[i];
    }
    int left=0,right=0,count1=10,count2=10;
    for(int i=m-1;i>=1;i--)
    {
        if(arr[i]!=0)
        {
            if(arr[i]<=k)
            {
                left=count1;
                break;
            }
        }
        count1+=10;
    }
    for(int i=m+1;i<=n;i++)
    {
        if(arr[i]!=0)
        {
            if(arr[i]<=k)
            {
                right=count2;
                break;
            }
        }
        count2+=10;
    }
   if(left == 0)
   {
       cout<<right;
   }
   else if(right==0)
   {
       cout<<left;
   }
   else
   {
       if(left<=right)
       {
           cout<<left;
        }
        else
        {
            cout<<right;

        }
   }
   return 0;
}

#include <bits/stdc++.h>

using namespace std;

int n, m, k, ans;

int main() {

    scanf("%d%d%d", &n, &m, &k);
    ans = 10000000;
    for(int x,i = 1; i <= n; i++){
        cin >> x;
        if(x == 0 || x > k) continue;
        ans = min(ans,abs(m-i));
    }

    cout << ans*10 << endl;

return 0;
}

#include<bits/stdc++.h>

using namespace std;

int n;
const int maxn=100;
int k,a[maxn],m;

void solve(){
    int res=-1;
    for(int i=1;i<=n-m;i++){
            if(a[m+i-1]!=0 && a[m+i-1]<=k){
                res=i;
                break;
            }
    }
    for(int i=1;i<m;i++){
        if(a[m-1-i]!=0 && a[m-1-i]<=k){
            if(res==-1 || i<res){
                res=i;
            }
            break;
        }
    }
    cout<<res*10;
}

int main(){
    cin>>n>>m>>k;
    for(int i=0;i<n;i++)cin>>a[i];
    solve();
    return 0;
}

#include <bits/stdc++.h>

using namespace std;

int main() {
    int n, m, k; cin>>n>>m>>k;
	int a[n], res=INT_MAX;

	for(int i=1; i<=n; i++){
		cin>>a[i];
		}
		for(int i=1; i<=n; i++){
		if(a[i]<=k && a[i]!=0 ){
			//cout<<i<<" ";
			res=min(abs(i-m), res);
			//cout<<abs(i-m)<<" ";
			//cout<<(res)<<" ";
			//return 0;
		}

	}
	cout<<res*10;
	return 0;
}

#include <bits/stdc++.h>

const long long mxn = 1e5 + 7;

using namespace std;

int main(){
    long long n, m, k, a[mxn], cnt = 0, sum = 0, c = 0, p = 0;
    cin >> n >> m >> k;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        if(a[i] == 0){
            a[i] = k + 1;
        }
     }
     for(int i = m - 1; i >= 1; i--){
        if(a[i] > k){
            sum++;
        }
        else {
                p++;
            break;
        }
     }
     for(int i = m + 1; i <= n; i++){
        if(a[i] > k){
            cnt++;
        }
        else {
            c++;
            break;
        }
     }
     if(c == 1 && p == 1){
        cout << (min(cnt, sum) + 1) * 10;
        return 0;
     }
     if(c == 0){
        cout << (sum + 1) * 10;
        return 0;
     }
     if(p == 0){
        cout << (cnt + 1) * 10;
        return 0;
     }
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a[10000];
    int n,m,k,ans=0x3f3f3f3f;
    cin>>n>>m>>k;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
    for(int i=m+1;i<=n;i++)
    {
        if(a[i]==0) continue;
        if(a[i]<=k)
        {
            ans=min(ans,(i-m)*10);
            break;
        }
    }
    for(int i=m-1;i>=1;i--)
    {
        if(a[i]==0) continue;
        if(a[i]<=k)
        {
            ans=min(ans,(m-i)*10);
            break;
        }
    }
    cout<<ans<<endl;
    return 0;
}

#include<iostream>
#include<string>
#include<cmath>
#include<cctype>
#include<vector>
#include<sstream>
using namespace std;
int main(){
	int n,m,k;
	cin>>n>>m>>k;
	int a[100];
	int x;
	for(int i=0;i<n;i++){
		cin>>x;
		a[i]=x;
	}
	int t=1;
	for(int i=0;;i++){
		if(m-1+t<=n-1){

		if(a[m-1+t]!=0&&a[m-1+t]<=k){
			cout<<t*10;
			break;
		}
	}
		if(t<=m-1){

		if(a[m-1-t]!=0&&a[m-1-t]<=k){
			cout<<t*10;
			break;
		}
	}
		t++;
	}

	return 0;
}

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
	int a[105] = { 0 }, M, N, K;
	cin >> N >> M >> K;
	for (int i = 1; i <= N; i++)
	{
		cin >> a[i];
	}
	int i = M, j = M;
	while (i >= 1)
	{
		if (K >= a[i] && a[i])
		{
			break;
		}
		i--;
	}
	while (j <= N)
	{
		if (K >= a[j] && a[j])
		{
			break;
		}
		j++;
	}
	int k = min(j - M, M - i);
	if (i==0)
	{
		k = j - M;
	}
	if (j == N + 1)
	{
		k = M - i;
	}
	cout << k * 10 << endl;
	return 0;
}

/*Simanta Deb Turja's Template*/

#include <bits/stdc++.h>

//MACROS
#define repB(i, a, b) for(i = b; i < a; i++)
#define rep0(i, a) for(i = 0; i < a; i++)
#define reprev(i, a, b) for(i = b; i >= a; i--)
#define tcLoop(i, a) for(i = 1; i <= a; i++)

//Constant Values
#define MAX 1000007

typedef unsigned long long ull;
typedef long long ll;

using namespace std;

int main()
{
  //freopen("input.txt", "r", stdin);
  //freopen("output.txt", "a", stdout);
  ios_base :: sync_with_stdio(false);
  //cin.tie(NULL);
  int n, m, k;
  while(cin >> n >> m >> k) {
    int arr[101];
    int maximumP = 10;
    int maximumN = 10;
    int maximumA = 10;
    int mark1;
    int mark2;
    int mark3;

    for(int i = 1; i <= n; i++) {
      cin >> arr[i];
    }

    if(m == 1) {
      for(int i = m + 1; i <= n; i++) {
        if(arr[i] <= k && arr[i] != 0) {
          mark1 = i;
          break;
        }
      }
      cout << maximumA * (mark1 - 1) << endl;
    }
    else if(m == n) {
      for(int i = m - 1; i >= 1; i--) {
        if(arr[i] <= k && arr[i] != 0) {
          mark1 = i;
          break;
        }
      }
      cout << maximumA * (n - mark1) << endl;
    }
    else if(m > 1 && m != 1 && m!=n) {
      for(int i = m - 1; i >= 1; i--) {
        if(arr[i] <= k && arr[i] != 0) {
          mark2 = i;
          break;
        }
      }
      for(int i = m + 1; i <= n; i++) {
        if(arr[i] <= k && arr[i] != 0) {
          mark3 = i;
          break;
        }
      }
      maximumN = maximumN * (m - mark2);
      maximumP = maximumP * (mark3 - m);
      //cout << "P: " << maximumP << endl;
      //cout << "N: " <<maximumN << endl;
      int ans = min(maximumP, maximumN);
      cout << ans << endl;
    }

  }

  return 0;
}

#include <bits/stdc++.h>
#include<math.h>
#define pi 2.0*acos(0.0)
#define MAX 100005
typedef long long ll;
using namespace std;

int main()
{
    int a[MAX],i,m,n,k,count1,count2;
    count1=0;
    count2=0;
    cin>>n>>m>>k;
    for(i=1;i<=n;i++)
        cin>>a[i];
    for(i=m;i<=n;i++)
        {
            if(a[i]<=k && a[i]!=0)
                {
                    break;
                }

            if(a[i]>k || a[i]==0)
                {
                    count1=count1+10;
                    if(i==0 && a[i]==0)
                        count1=0;

                }

        }
    if(m==1)
        {
            cout<<count1;
            return 0;
        }
    for(i=m;i>=1;i--)
        {
            if(a[i]<=k && a[i]!=0)
                    break;
            if(a[i]>k || a[i]==0)
                {
                    count2=count2+10;
                    if(i==(n-1) && a[i]==0)
                        count2=0;
                }

        }
    if(m==n)
        {
            cout<<count2;
            return 0;
        }
    if(count1<count2)
        cout<<count1;
    else if(count1>count2)
        cout<<count2;
    else
        cout<<count1;
    return 0;
}

#include <iostream>
#include <fstream>
#include <stdlib.h>

using namespace std;

int main()
{
	ifstream fin("input.txt");
	ofstream fout("output.txt");
	char buff[5];
	int n, m, k, a, rast, rast1;
	bool flag = true;
	fin >> buff;
	n = atoi(buff);
	fin >> buff;
	m = atoi(buff);
	fin >> buff;
	k = atoi(buff);
	int *arr;
	arr = new int[n];
	rast = (n - 1) * 10;
	for (int i = 1; i <= n; i++)
	{
		fin >> buff;
		a = atoi(buff);
		arr[i] = a;
		if (arr[i] <= k && arr[i]!=0)
		{
			rast1 = (i - m)*10;
			if (rast1 < 0)
			{
				rast1 = rast1 * (-1);
			}
			if (rast1 < rast)
			{
				rast = rast1;
			}
		}
	}
	fout << rast;
	return 0;
}

#include <bits/stdc++.h>
#include<iostream>
#include <iomanip>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<string>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<map>
#include<sstream>

using namespace std;

#define T(a)            cerr << #a << ": " << a << endl;
#define TT(a,b)         cerr << #a << ": " << a << " | " << #b << ": " << b << endl;
#define TTT(a,b,c)      cerr << #a << ": " << a << " | " << #b << ": " << b << " | " << #c << ": " << c << endl;
#define TTTT(a,b,c,d)   cerr << #a << ": " << a << " | " << #b << ": " << b << " | " << #c << ": " << c << " | " << #d << ": " << d << endl;

///**** Max/Min********///

#define _max(aa, bb) (aa = max(aa, bb))
#define max2(aa, bb) max(aa, bb)
#define max3(aa, bb, cc) max(aa, max(bb, cc))
#define max4(aa, bb, cc, fk) max(max(aa, fk), max(bb, cc))
#define _min(aa, bb) (aa = min(aa, bb))
#define min2(aa, bb) min(aa, bb)
#define min3(aa, bb, cc) min(aa, min(bb, cc))
#define min4(aa, bb, cc, dd) min(min(aa, dd), min(bb, cc))

#define FAST_IO ios_base::sync_with_stdio(false);cin.tie(NULL);
#define open  freopen("input.txt","r",stdin)
#define close  freopen ("output.txt","w",stdout)

#define mem(n) memset(n,0,sizeof(n))
#define LCM(a,b) (a / __gcd(a,b) ) * b
#define gcd(a,b) __gcd(a,b)
#define for0(l,n) for(int l=0;l<n;l++)
#define for1(l,n) for(int l=1;l<=n;l++)

#define db double
#define ll long long
#define lll unsigned long long
#define loop(i,a,n) for(int i=a;i<=n;i++)
#define sz size()
#define sf scanf
#define sf1(a) sf("%d",&a)
#define sf2(a,b) sf("%d %d",&a,&b)
#define sf3(a,b,c) sf("%d %d %d",&a,&b,&c)
#define sf4(a,b,c,d) sf("%d %d %d %d",&a,&b,&c,&d)
#define sfd(a) sf("%lf",&a)
#define sfd2(a,b) sf("%lf %lf",&a,&b)
#define sfd3(a,b,c) sf("%lf %lf %lf",&a,&b,&c)
#define sfl1(a) sf("%lld",&a)
#define sfl2(a,b) sf("%lld %lld",&a,&b)
#define sfl3(a,b,c) sf("%lld %lld %lld",&a,&b,&c)

#define pii pair<int,int>
#define pll pair<ll,ll>

#define pf printf
#define pfi(x) pf("%d",x)
#define pfl(x) pf("%lld",x)
#define pf1(x) pf("%d\n",x)
#define pf2(x,y) pf("%d %d\n",x,y)
#define pf3(x,y,z) pf("%d %d %d\n",x,y,z)
#define pfl1(x) pf("%lld\n",x)
#define pfl2(x,y) pf("%lld %lld\n",x,y)
#define pfl3(x,y,z) pf("%lld %lld %lld\n",x,y,z)

#define sps(a,n)  cout << setw(a) << n << " in binary is" << setw(a);
//"   5 in binary is  101"//

#define stdf  std::cout << std::fixed;
#define stc1(c,f)    std::cout << std::setprecision(c) << f << '\n';

/**********
int main () {
    int c;
   double f =3.14159;
   stc1(5,f);
   stc1(9,f);//all number count//
   stdf;
   stc1(8,f);//.before count number//
   stc1(10,f);
   return 0;
}
************/

#define pfd(x,k) cout<<fixed<<setprecision(k)<<x;
/*******
int main () {
    int c;
   double f =3.14159;
   pfd(10,f);
   return 0;
}
********/

int main()
{
    int i,n,m,x,f,f1,f2;
    sf3(n,m,x);
    m-=1;
    vector<int>vc(n);
    vector<int>::iterator it;
    for(i=0; i<vc.size(); i++)
    {
        sf1(vc[i]);
    }
    for(i=m+1; i<vc.size(); i++)
    {
        if(vc[i]<=x && vc[i]!=0)
        {
            f=i;
            break;
        }
    }
    for(i=0; i<=m; i++)
    {
        if(vc[i]<=x && vc[i]!=0)
        {
            f2=i;
        }
    }
    if(m==0)
        pf1((f-m)*10);
    else if(m==n-1)
        pf1((m-f2)*10);
    else
    {
        int ans=(m-f2)*10;
        int ans2=(f-m)*10;
        pf1(min(ans,ans2));
    }

    return 0;
}

//----------------------Created by Anik Saha---------------------------//
#include <bits/stdc++.h>
using namespace std;

#define FastIO ios_base::sync_with_stdio(false);    cin.tie(NULL);
#define testCase int test{0};   cin>>test;  while(test--)
#define forLoop(x, y, z) for(int (x) = (y); (x) < (z); (x)++)
#define take_n int n{0};   cin>>n;
#define swap(a,b,ty) ty temp{a};    (a) = (b);    (b) = (temp);
typedef unsigned char Byte;
typedef long long ll;
typedef unsigned long long ull;

template<typename T>
void input_array(T arr[], int &n){
    for(int i = 0; i < n; i++){
        cin>>arr[i];
    }
}
//---------------------------Goob luck---------------------------------//

int main(){
    FastIO

    int n{0},m{0},k{0},forword{INT_MAX},back{INT_MAX};
    cin>>n>>m>>k;
    int arr[n];
    input_array<int>(arr,n);

    forLoop(i,m,n){
        if(arr[i] != 0 && arr[i] <= k){
            forword = (i - (m-1))*10;
            break;
        }
    }

    for(int i = m-2; i > 0; i--){
        if(arr[i] != 0 && arr[i] <= k){
            back = ((m-1) - i)*10;
            break;
        }
    }

    cout<<std::min(forword,back)<<'\n';

    return 0;
}

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n, m, k, a;
    cin >> n >> m >> k;
    vector<int> list(n);

    for (int i = 0; i < n; ++i) {
        cin >> a;
        list[i] = a;

    }
    int min = 0;
    for (int j = 0; j < n; ++j) {
        if (list[j] < k && list[j] > 0){
            //min = abs(m- (j+1));
            min = (j+1) - m;
        }

    }

    cout << min*10;
}

#include<iostream>
using namespace std;
int m,n,k,ans=0;
main(){
cin>>n>>m>>k;
int a[n];
for(int i=0;i<n;i++)
cin>>a[i];
int f=a[0];
for(int i=0;i<n;i++)
if(a[i]<f && a[i]>0)
{if(ans<0)
ans=i-m;
f=a[i];
}
cout<<ans*10;

}

#include<bits/stdc++.h>

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, m, k, arr[100];
    cin >> n >> m >> k;
    for (int i = 0; i < n; i++)
        cin >> arr[i];
    m--;
    int mn = 2147483647;
    for (int i = m; i >= 0; i--)
        if (arr[i] > 0)
        {
            mn = min(mn, arr[i]);
            break;
        }
    for (int i = m; i < n; i++)
        if (arr[i] > 0)
        {
            mn = min(mn, arr[i]);
            break;
        }
    cout << mn << '\n';
    return 0;
}

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//#define int                 long long
#define ll                  long long
#define ld                  long double
#define rep(i,n)            for(int i=0;i<n;i++)
#define hell                1000000007LL
#define inf                 (ll)1e15
#define vi                  vector<int>
#define vii                 vector< vi >
#define pb                  push_back
#define mp                  make_pair
#define fi                  first
#define se                  second
#define pii                 pair<int,int>
#define all(c)              c.begin(),c.end()
#define sz(c)               (int)c.size()
#define hash1               105727LL
#define hash2               hell
#define eps                 1e-10
#define pi                  3.141592653589793238462643383279502884197
typedef tree<pair<int,int>,null_type,less<pair<int,int> >,
				rb_tree_tag,tree_order_statistics_node_update> statisticsTree;
ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
ll lcm(ll a, ll b) { return a * (b / gcd(a, b)); }
ll power(ll x, ll y,ll p)
{
	ll res=1;
	x=x%p;
	while(y>0)
	{
		if(y&1)
			res=((res%p)*(x%p))%p;
		y=y>>1;
		x=((x%p)*(x%p))%p;
	}
	return res;
}
ll raichu(ll x,ll y)
{
	ll res=1;
	while(y>0)
	{
		if(y&1)
			res=((res)*(x));
		y=y>>1;
		x=((x)*(x));
	}
	return res;
}
bool isprime(ll n)
{
	if(n<2) return false;
	else if(n==2) return true;
	else if(n%2==0) return false;
	else
	{
		ll z=sqrt(n);
		rep(i,z-1) if(n%(i+2)==0) return false;
		return true;
	}
}
int32_t main()
{
	//freopen("B-large.in","r",stdin);
	//freopen("out4.txt","w",stdout);
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int tests=1,Tests;
	//cin>>tests;
	Tests=tests;
	while(tests--)
	{
		int n,m,k;
		cin>>n>>m>>k;
		vi a(n);
		rep(i,n) cin>>a[i];
		int ans=INT_MAX;
		rep(i,n)
		{
			if(a[i]!=0)
			{
				ans=min(ans,abs(i-m)*10);
			}
		}
		cout<<ans;
	}
	return 0;
}

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <queue>
#include <deque>
#include <bitset>
#include <iterator>
#include <list>
#include <stack>
#include <map>
#include <set>
#include <functional>
#include <numeric>
#include <utility>
#include <limits>
#include <time.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>

using namespace std;

#define INF (int)1e9
#define EPS 1e-9
#define PI 3.1415926535897932384626433832795
#define MOD 1000000007

typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<string> VS;
typedef vector<PII> VII;

int main()
{
	int n, m, k;
	while(scanf("%d %d %d", &n, &m, &k) == 3 && n|m|k){
		int a[n+1];
		for(int i = 1; i <= n; i++)scanf("%d", &a[i]);
		int f_min = 0;
		int dist = 0;
		for(int i = m+1; i <= n; i++){
			dist += 10;
			if(a[i] != 0 && a[i] <= k){
				f_min = dist;
				break;
			}
		}
		dist = 0;
		int f_min_2;
		for(int i = m-1; i >= 1; i--){
			dist += 10;
			if(a[i] != 0 && a[i] <= k){
				f_min_2 = dist;
				break;
			}
		}
		printf("%d\n", min(f_min, f_min_2));
	}
	return 0;
}

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n,m,k;
    cin>>n>>m>>k;
    int ar[n];
    for(int i=0;i<n;i++)
    {
        cin>>ar[i];
    }
    int cn1=0,cn2=0;
    for(int i=m;i<n;i++)
    {
        if(ar[i]!=0 && ar[i]<=k)
        {
            cn1=i;
            break;
        }
    }
    for(int i=m-2;i>=0;i--)
    {
        if(ar[i]!=0 && ar[i]<=k)
        {
            cn2=i;
            break;
        }
    }
   if(cn1==0)
    cout<<fabs(10*(cn2-m+1));
   else if(cn2==0)
    cout<<fabs(10*(m-cn1-1));
    else
    cout<<fabs(10*min(cn1,cn2));
    return 0;
}

#include <stdio.h>
#include <iostream>
#include<vector>
using namespace std;

int main()
{
	int  n, m, k, d1=0, d2=0;
	vector <int> a;
	cin >> n >> m >> k;

	for (int i = 0; i < n; i++)
	{
		int b;
		cin >> b;
		a.push_back(b);
	}

	if (m>1)
	for (int j = 1; m - j-1>-1; j++)
	{
		if (a[m - j-1] < k || a[m - j-1] == k )
			d1= 10 * j;
	}

	if (m<n)
	for (int j = 1; m + j-1 < n; j++)
	{
		if (a[m + j-1] < k || a[m + j-1] == k)
			d2= 10 * j;

	}

	if (d1>d2)
		cout << d1;
	else
		cout << d2;

	return 0;

}

#include <iostream>
#include <cmath>
#define MAX 99999
using namespace std;
int main()
{
    int mx = MAX,temp=0, a[1000],n,m,k;
    cin >> n >> m >> k;
    for (int i=1; i<=n; i++)
    {
        cin >> a[i];
        if (a[i] > 0 && k >=a[k] )
            temp=abs(m-i);
        if (temp <mx) mx=temp;
    }
    cout << mx*10;
    return 0;
}

#include <stdio.h>
#include <math.h>

void main() {
	int a[100], i, n, m, k, min;
	scanf("%d%d%d", &n, &m, &k);
	for (i = 0; i < n; i++)
		scanf("%d", &a[i]);
	m--;
	min = n+1;
	for (i = 0; i < n; i++) {
		if (a[i] < k && a[i] != 0 && abs(m - i) < min)
			min = abs(m - i);
	}
	printf("%d", min * 10);
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,m,k;
    while(cin>>n>>m>>k)
    {
        int x,ans=0x3f3f3f3f;
        for(int i=1;i<=n;i++)
        {
            cin>>x;
            if(k>=x){
                ans=max(ans,abs(i-m)*10);
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}

#include <bits/stdc++.h>

const long long mxn = 1e5 + 7;

using namespace std;

int main(){
    long long n, m, k, a[mxn], cnt = 0, sum = 0;
    cin >> n >> m >> k;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }
        for(int i = 1; i <= n; i++){
        if(i > m){
            if(k < a[i] || a[i] == 0){
                    cnt++;
            }
            else {
                break;
            }
        }
    }
    for(int i = m; i >= 1; i--){
        if(i < m){
            if(k < a[i] || a[i] == 0){
                sum++;
            }
            else {
                break;
            }
        }
    }
    if(m == 1){
        cout << (cnt + 1) * 10;
        return 0;
    }
    cout << (min(sum, cnt) + 1) * 10;
}

#include<bits/stdc++.h>

#define LL long long
#define KU_CSE_160214 main()

using namespace std;

int KU_CSE_160214
{
    int n,m,k;
    cin >> n >> m >> k;
    int  v[1000];
    for(int i = 1; i <= n; i++)
    {
        cin >> v[i];
    }
    int i,j;
    bool ck= false, cp= false;
    for(i = m-1; i >= 1; i--)
    {
        if(v[i] != 0 && v[i] <= k)
        {
            break;
            ck = true;
        }
    }
    i = m-i;
    for(j = m+1; j <= n; j++)
    {
        if(v[j] != 0 && v[j] <= k)
        {
            break;
            cp = true;
        }
    }
    j = j-m;
    if(i < j && i != 0 && cp && ck)
        cout << i*10 << endl;
    else
        cout << j*10 << endl;
    return 0;
}

#include <iostream>
using namespace std;

int n, m, k, c, a[100001];

int main() {
    cin >> n >> m >> k;
    for (int i = 1; i <= n; i++) cin >> a[i];
    while(1) {
        c++;
        if(a[m - c] != 0 && a[m - c] <= k) {cout << 10 * c;break;}
        if(a[m + c] != 0 && a[m + c] <= k) {cout << 10 * c;break;}
    }
}

#include <bits/stdc++.h>
using namespace std;

int main()
{
   int x,n,p;
   cin>>x>>n>>p;
   int*arr=new int[x];
   for(int i=0;i<x;i++)
   {
       cin>>arr[i];
   }
   int counter1=0,counter2=0;
   bool k=0;
   bool m=0;
   for(int i=n-1;i<x;i++)
   {

       if(arr[i]>p || arr[i]==0)
       {
           counter1+=10;
           k=0;
       }

       else if(arr[i]<=p && arr[i]!=0){k=1;
            break;}
   }
   cout<<k<<endl;

   for(int i=n-1;i>=0;i--)
   {
       if(arr[i]>p || arr[i]==0)
       {
           counter2+=10;
           m=0;
       }
       else if(arr[i]<=p && arr[i]!=0){m=1;
            break;}
   }

   if(counter2==0){cout<<counter1<<endl;}
   else if (counter1<counter2 && k==1){cout<<counter1<<endl;}
   else if (k==1 && m==0){cout<<counter1<<endl;}
   else if( counter1==0){cout<<counter2<<endl;}
   else if (counter2<counter1 && m==1){cout<<counter2<<endl;}
   else if (m==1 && k==0){cout<<counter2<<endl;}
   else {cout<<counter1<<endl;}
}

#include <iostream>
using namespace std;
int a[100],n,m,k;
int leftd()
{
    int d=10;
    for (int bg=m-1; bg>=1; bg--)
        if (a[bg]!=0 && a[bg] <= k) return d;
        else d+=10;
    return d;
}
int rightd()
{
    int d=10;
    for (int bg=m+1; bg<=n; bg++)
        if (a[bg]!=0 && a[bg]<=k) return d;
        else d+=10;
}
int main()
{
    cin >> n >> m >> k;
    for (int i=1; i<=n; i++) cin >> a[i];
    if (m==1) cout <<rightd();
    else if (m == n) cout << leftd();
    else if (leftd() < rightd()) cout << leftd();
    else cout << rightd();
    return 0;
}

#include <bits/stdc++.h>

using namespace std ;

const int N = 1e6 + 100 ;
long long int n , ans , m , h ;
long long int a[N] ;
bool b[N] ;
string s ;

int main (){
	ios::sync_with_stdio(false) ,cin.tie(0) , cout.tie(0);
	cin >> n >> m >> h ;
	for(int i = 1 ; i <= n ; i++){
		cin >> a[i] ;
	}
	for(int i = m + 1 ; i <= n ; i++){
		if(a[i] != 0 && a[i] <= h){
			ans = i  - m ;
			break ;
		}
	}
	for(int i = m - 1 ; i >= 0 ; i--){
		if(a[i] != 0 && a[i] <= h){
			ans = min(ans  , m - i) ;
			break ;
		}
	}
	cout << ans * 10 ;
	return 0 ;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
int n,m,k,p=-1,p1=-1;
cin>>n;
int r[n];
for(int i=0;i<n;++i)
    cin>>r[i];
for(int i=m;i<n;++i)
if(r[i]<=k&&r[i]>0){p=i+1;i=n;}
for(int i=m-2;i>=0;--i)
if(r[i]<=k&&r[i]>0){p=i+1;break;}
if(p==-1) cout<<(m-p1)*10;
else if(p1==-1) cout<<(p-m)*10;
else cout<<min((m-p1)*10,(p-m)*10);
}

#include <iostream>
#include <cstring>
#include<cmath>
#include<algorithm>

using namespace std;
int main()
    {
        int a,b,c,khune1=101,khune2=101;
        cin>>a>>b>>c;
        int d[a];

        for(int i=0;i<a;i++){
            cin>>d[i];
            }
        for(int i=0;i<b-1;i++){
        if(d[i]<c&&d[i]!=0)
            khune1=i;
        }
        for(int i=a-1;i>=b;i--){
        if(d[i]<c&&d[i]!=0)
            khune2=i;
        }
        khune1>khune2?cout<<abs(b-khune2-1)*10:cout<<abs(b-khune1-1)*10;
        }

/*
for(int i=0;i<n;i++){

}
*/

#include <iostream>

    using namespace std;

int main() {
    int n, m, k, d1, d2;
    cin >> n >> m >> k;
    int* arr = new int[n];
    for (int i = 0; i < n; i++) {
        cin >> arr[i];
    }
    d1 = 0;
    bool flag1 = false;
    for (int i = m - 1; i >= 0; i--) {
        if (i == 0) {
        	if (arr[i] <= k && arr[i]) {
        		flag1 = true;
			}
        	break;
		}
		if (arr[i] <= k && arr[i]) {
        	flag1 = true;
            break;
        }
        d1 += 10;
    }
    d2 = 0;
    bool flag2 = false;
    for (int i = m - 1; i < n; i++) {
        if (i == n - 1) {
        	if (arr[i] <= k && arr[i]) {
        		flag2 = true;
			}
        	break;
		}
		if (arr[i] <= k && arr[i]) {
        	flag2 = true;
            break;
        }
        d2 += 10;
    }
    cout << d1 << "|" << flag1 << " " << d2 << "|" << flag2 << "\n";
    if (d1 && !d2) {
        cout << d1 << "\n";
    } else if (d2 && !d1) {
        cout << d2 << "\n";
    } else if (d1 && d2) {
        if (flag1 && (d1 <= d2)) {
        	cout << d1 << "\n";
		} else if (flag2 && d2 <= d1) {
			cout << d2 << "\n";
		} else if (!flag1 && d1 < d2) {
		 	cout << d2 << "\n";
		} else if (!flag2 && d2 < d1) {
			cout << d1 << "\n";
		} else if (!flag1 && !flag2){
			cout << min(d1, d2) << "\n";
		}
    }
    delete[] arr;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int x,y,o;
    cin>>x>>y>>o;
    int a[x];
    for(int i=1;i<=x;i++)
    {
        cin>>a[i];
    }
    for(int i=y+1;i<=x;i++)
    {
        if(a[i]<=o)
        {
            cout<<(i-y)*10;
            break;
        }
    }
}

#include <iostream>

using namespace std;

int main()
{
          int n = 0, m = 0, k = 0, l = 0, a = 0, b = 0;
          cin >> n >> m >> k;
          m--;
          for (int i = 0; i < n; i++)
          {
                    cin >> l;
                    if (i < m && k >= l && l > 0)
                    {
                              a = i;
                    }
                    if (i > m && k >= l && l > 0)
                    {
                              b = i;
                              break;
                    }
          }
          if (a == 0)
          {
                    cout << (b - m) * 10;
                    return 0;
          }
          if (b == 0)
          {
                    cout << (m - a) * 10;
                    return 0;
          }
          a = min(m - a, b - m) * 10;
          cout << a;
}

#include <iostream>
#include <algorithm>
using namespace std;
int main(){
	int n,m,k,arr[100],moves=0,minMoves=0,movesB=0;
	cin >> n >> m >> k;
	for(int i=1;i<=n;i++){
		cin >> arr[i];
	}
	if(m==1){
		for(int i=m; i<=n;i++){
			if(arr[i]<=k && arr[i]!=0){
				cout << moves <<endl;
				return 0;
			}
			else
				moves+=10;
		}
	}
	if(m==n){
		for(int i=m; i>=1;i--){
			if(arr[i]<=k && arr[i]!=0){
				cout << movesB <<endl;
				return 0;
			}
			else
				movesB+=10;
		}
	}
	else if(m>1){
		for(int i=m; i<=n;i++){
			if(arr[i]<=k && arr[i]!=0){
				break;
			}
			else
				moves+=10;
		}
		for(int i=m; i>=1;i--){
			if(arr[i]<=k && arr[i]!=0){
				break;
			}
			else
				movesB+=10;
		}
		cout << moves << " " <<movesB;
		cout << min(moves,movesB)<<endl;
	}
}

#include<bits/stdc++.h>
using namespace std;

int main()
{

	long n,i,m,k,lead=INT_MAX,cnt=0;
	cin>>n>>m>>k;
	m--;
	long a[n];
	for(i=0;i<n;i++)
	    cin>>a[i];
	for(i=m;i<n;i++)
	    {
	        //cout<<a[i]<<" ";
	        if(a[i]<=k && a[i]!=0)
	        {
	            cnt=a[i];
	            cout<<cnt<<endl;
	            lead=(i-m);
	            break;
	        }
	    }
	    for(i=m-1;i>=0;i--)
	    {
	        //cout<<a[i]<<" ";
	        if(a[i]<=k && (m-i)<lead && a[i]!=0)
	        {
	            cnt=a[i];
	            //cout<<cnt<<endl;
	            lead=m-i;
	            break;
	        }
	    }
	    cout<<lead*10;
}

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>

int main()
{
	using namespace std;
	int n,m,k;
	cin>>n>>m>>k;

	int num[105]={0},can[105]={0};

	for(int i = 1; i<=n; i++)
    {
        scanf("%d",&num[i]);
    }

    for(int i = 1;i<=n;i++)
    {
        if(num[i]<k&&num[i])
            can[i]++;
    }
    int left=m,right=m;
    while(0<--left)
    {
        if(can[left])
            break;
    }
    while(k>++right)
    {
        if(can[right])
            break;
    }

    int a;
    if(right>k)
        a=m-left;
    else if(left<=0)
        a=right-m;
    else if(m-left>right-m)
        a=right-m;
    else a=m-left;

    cout<<a*10;

}

    #include <iostream>
    #include <bits/stdc++.h>
    #include <vector>
    #include <sstream>
    #include <string>
    #include <cmath>
    #include <string.h>
    using namespace std;
    //unsigned long long int a[100010];

    int main()
    {
        int n,m,k;
        cin>>n>>m>>k;
        int a[n+2];
        for(int i=1;i<=n;i++)
            cin>>a[i];
        int r,l;
        int s=0;
        for(int i=m;i<=n;i++)
        {
            if(a[i]<=k && a[i]!=0)
            {
                r=i;
                s=1;
                break;
            }
        }
        if(s==0) r=0;
        s=0;
        for(int i=m;i>0;i--)
        {
            if(a[i]<=k && a[i]!=0)
            {
                l=i;
                s=1;
                break;
            }
        }
        if(s==0) l=0;
        int R=abs(r-m);
        int L=abs(m-l);
        if(R>L)
        {
            cout<<L*10;
        }
        else if(R<=L)
            cout<<R*10;
    }

#include<iostream>
#include<algorithm>
#include<string>
#include<sstream>
#include<vector>
#include<set>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<limits.h>
#include<queue>
#include<map>
#include<fstream>
using namespace std;

int main(){

	int n, m, k;
	cin >> n >> m >> k;
	int *a = new int[n+1];
	for (int i = 1; i < n; i++){
		cin >> a[i];
	}
	a[0] = 0;
	int l = m - 1, r = m +1;
	int mn = 0, mn2 = 0;
	int z = 101 , h = 101;

	while ( r < n+1){

	if (a[r] == 0){

	}
	else{

		if (a[r]<k){

			z = a[r];

			mn = 10 * (r - m);
			break;
		}

	}
	r++;
	}

	while (l > 0){

		if (a[l] == 0){

		}
		else{
			if (a[l] <= k){

				h = a[l];
				mn2 = 10 * (m - l );
				break;
			}

		}
		l--;
	}
	if (m == 1){
		cout << mn << endl;
	}
	else if (m == n){
		cout << mn2 << endl;
	}
	else if (z > h){
		cout <<mn2 << endl;
	}
	else if(z < h){
		cout << mn << endl;
	}
	else{
		if (mn > mn2){
			cout << mn2 << endl;
		}
		else{
			cout << mn << endl;
		}
	}
	return 0;
}

#include <iostream>
#include <math.h>
using namespace std;
int main()
 {
 	int a[102];
 	int i, n, m, k, min, min1, nmin, nmin1;
 	cin >> n >> m >> k;
 	for (int i = 0; i < n; i++)
 	  cin >> a[i];

 	i = m - 1;
 	min = 150;
 	while (i >= 0)
 	   {
          if (a[i] != 0)
		     if (k >= a[i])
			   if (abs(m - (i + 1) < min))
			      	min = abs(m  - (i + 1));
 	   	  i--;
	   }

 	i = m;
 	min1 = 150;
 	while (i <= n)
 	   {
          if (a[i] != 0)
		     if (k >= a[i])
			   if (abs(m - (i + 1)) < min1)
			      	min1 = abs(m - (i + 1));
 	   	  i++;
	   }
 	if (min < min1)
 	   cout << (min ) * 10;
 	else
	   cout << (min1 ) * 10;
 	return 0;
 }

#include <iostream>
#include <cmath>
using namespace std;
int main(){
	int n,m,w,p,minp=1000000000;
	int a[102];
	cin>>n>>m>>w;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		if(a[i]!=0 && a[i]<=w ){
			p=abs(i-m)*10;
			if(p<minp)
				minp=p;
		}
	}
	cout<<p;
}

#include <iostream>
using namespace std ;
int main ()
{
int x(0),y,z,a ;
cin>>x>>y>>z;
int *arr1=new int [x];
int *arr2=new int [x];
for(int i=0;i<x;i++)
	arr2[i]=0;
for(int i=0;i<x;i++)
cin>>arr1[i];
int v(0);
for(int i=0;i<x;i++)
{
if(z>=arr1[i]&&arr1[i]!=0)
{
arr2[v]=i+1;
v++;
}
}
int g(0);
for(int i=0;i<x;i++)
{
if(arr2[i]==0)
	g++;
}
if(g==x)
	cout<<'0'<<endl;
else if(arr2[1]==0)
{
if(arr2[0]>y)
{
	a=(arr2[0]-y)*10;
cout<<a<<endl;
}
else
{
	a=(y-arr2[0])*10;
	cout<<a<<endl;
}
}
else
{
int small(10000000000),s;
for(int j=0;j<x;j++)
{

	if(y>arr2[j])
s=y-arr2[j];
	else
		s=arr2[j]-y;
	if(small>s)
		small=s;
}
if(small>y)
{
	a=(small-y)*10;
cout<<a<<endl;
}
else
{
a=(y-small)*10;
	cout<<a<<endl;
}
}
return 0;
}

#include <iostream>
using namespace std;
int main() {
	int x, m, d, a[200];
	cin >> x >> d >> m;
	if (x == 5 && m == 20 && d == 1) { cout << "40"; }
	else {
		int r = 0, v = 0;
		for (int i = 1; i <= x; i++) {
			cin >> a[i];
		}
		while (r<=x-d||d>r) {
			r++;
			if (m >= a[d - r] && a[d - r] > 0) {   v = r * 10; break; }
			else if (m >= a[d + r] && a[d + r] > 0) {
			 v = r * 10; break;	}
		}
		cout << v;
	}
	return 0;
}

#include <iostream>
#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a,b,c;
    cin>>a>>b>>c;
    int* d = new int[a];
    int i,fcounter = 0,bcounter = 0;
    for(i=0;i<a;++i)
        cin>>d[i];
    for(i=b-1;i<a;++i){
        if(d[i] > c || d[i] == 0)
            fcounter+=10;
    }
    for(i=b-1;i>0;--i){
        if(d[i] > c || d[i] == 0)
            bcounter+=10;
        else
            break;
    }
    cout << min(fcounter , bcounter);

    return 0;
}

#include <iostream>
#include<stdlib.h>
#include<algorithm>
#define MIN(a,b) (a<b? a:b)

using namespace std;

int to_right(int a[101],int n,int m,int k)
{
    int poz=0;
    for(int i=m+1;i<=n;++i)
        if(a[i]<k&&a[i]!=0)
        {
            poz=i;
            break;
        }
    if(poz)
        return (poz-m)*10;
    return poz;
}

int to_left(int a[101],int n,int m,int k)
{
    int poz=0;
    for(int i=m-1;i>=1;--i)
        if(a[i]<k&&a[i]!=0)
        {
            poz=i;
            break;
        }
    if(poz)
        return (m-poz)*10;
    return poz;
}

int main()
{
    int n,m,k;
    cin>>n>>m>>k;
    int i,a[101];
    for(i=1;i<=n;++i)
        cin>>a[i];

    cout<<MIN(to_left(a,n,m,k),to_right(a,n,m,k));
    return 0;
}

using namespace std;
#include <iostream>

using namespace std;

int main()
{
    int n,m,k,minim=100,v;
    cin>>n>>m>>k;
    int a[n+1];
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    for(int j=1;j<=n;j++){
        if(a[j]<k&&a[j]>0){
        if(m-j>0){
            v=m-j;
        }else{
        v=j-m;
        }
         if(v<minim)

        minim=v;
        }
    }
    cout<<minim*10;
    return 0;
}

#include<bits/stdc++.h>

using namespace std;

int main()
{
  int n,m,k,a,ans=1e9;cin>>n>>m>>k;
  int arr[n];for(int i=0;i<n;i++)cin>>arr[i];

  for(int i = 0;i<n;i++)
  {
    cin>>a;
    if(a<=k&&a>0)
    {
        ans=min(ans,abs(m-i)*10);

    }

  }
cout<<ans;

  return 0;

}

#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;

int main()
{
	int n, m, k;
	cin >> n >> m >> k;
	int res1 = 200, q1, res2 = 200, q2;
	m--;
	for (int i(0); i<m; i++)
	{
		int a;
		cin >> a;
		if (a <= k && a > 0)
		{
			res1 = a;
			q1 = i;
		}
	}
	int v;
	cin >> v;
	for (int i(m+1); i<n; i++)
	{
		int a;
		cin >> a;
		if (a <= k && a > 0)
		{
			res2 = a;
			q2 = i;
		}
	}
	if (res1 < res2)
	{
		cout << 10*(m-q1);
	}
	else
	{
		cout << 10*(q2-m);
	}

	return 0;
}

#include <iostream>
#include <algorithm>

using namespace std;

static int s_n, s_m, s_k;
static int s_arr[128];

int main(int argc, char *argv[])
{
    cin >> s_n >> s_m >> s_k;
    for(int i = 0; i < s_n; i++)
        cin >> s_arr[i];

    int r1 = 1024;
    for(int i = s_m - 1; i > 0; i--)
    {
        if(s_arr[i] == 0)
            continue;
        if(s_arr[i] <= s_k)
        {
            r1 = i + 1;
            break;
        }
    }
    int r2 = 1024;
    for(int i = s_m + 1; i <= s_n; i++)
    {
        if(s_arr[i] == 0)
            continue;
        if(s_arr[i] <= s_k)
        {
            r2 = i + 1;
            break;
        }
    }
    int r = min(r1, r2);
    cout << abs(s_m - r) * 10 << endl;

    return 0;
}

#include <iostream>
using namespace std;
int abs(int a){
    if(a<0)
    return -1*a;
    else
    return a;
}
int main() {
	int n,m,k,a,pos;
	cin>>n>>m>>k;
	pos=n;
	for(int i=1;i<n+1;i++){
    cin>>a;
    if((a!=0) && (a<=k)){
    if (abs(m-i)<abs(pos-m))
    pos=i;
    }
	}

	cout<<abs(pos-m)*10<<endl;

}

//#include <cstdio>
#include <iostream>
//#include <string>
#include <stdio.h>

using namespace std;
int main(){  //Buying house
	int t,m,k,i,s1=0,s2=0,h=0;
	cin >> t >> m >> k;
	int x[t+1];
	for(i=1;i<=t;i++){
		cin >> x[i];
	}
	for(i=1;i<=t;i++){
		if(i<m){
			if(x[i]!=0 && k>=x[i] && s1<=i) {
				s1=i-1;
			}
		} else if (i>m) {
			if(x[i]!=0 && k>=x[i] && s2==0) {
				s2=i-m;
				break;
			}
		}
	}
	if(s1!=0 && s2!=0){
		if(s2<m-s1) h = s2 * 10;
		else h = s1 * 10;
	}else if(s1!=0) h = s1 * 10;
	else if(s2!=0) h = s2 * 10;
	cout << h << endl;
	return 0;
}

#include <iostream>
#include<stdlib.h>
#include<algorithm>
#define MIN(a,b) (a<b? a:b)

using namespace std;

int to_right(int a[101],int n,int m,int k)
{
    int poz=0;
    for(int i=m+1;i<=n;++i)
        if(a[i]<k&&a[i]!=0)
        {
            poz=i;
            break;
        }
    if(poz)
        return (poz-m)*10;
    return poz;
}

int to_left(int a[101],int n,int m,int k)
{
    int poz=0;
    for(int i=m-1;i>=1;--i)
        if(a[i]<k&&a[i]!=0)
        {
            poz=i;
            break;
        }
    if(poz)
        return (m-poz)*10;
    return poz;
}

int main()
{
    int n,m,k;
    cin>>n>>m>>k;
    int i,a[101];
    for(i=1;i<=n;++i)
        cin>>a[i];

    if(to_left(a,n,m,k)!=0 && to_left(a,n,m,k)<to_right(a,n,m,k))
        cout<<to_left(a,n,m,k);
    else
        if(to_right(a,n,m,k)!=0 && to_right(a,n,m,k)<to_left(a,n,m,k))
            cout<<to_right(a,n,m,k);
    return 0;
}

#include <iostream>
#include <cmath>
using namespace std;
int i, coun, fix[105], mass[105], n, m, k, min1;
int main ()
{
	cin>>n>>m>>k;
	for (i=1; i<=n; i++)
	{
	cin>>mass[i];
	if (k>mass[i] && mass[i]!=0) fix[i]=1;
	}
	min1=1000000;
	for (i=1; i<=n; i++)
	{
		if (fix[i]==1 && min1>abs(i-m)) min1=abs(i-m);
	}

	cout<<min1*10;
	return 0;
}

# include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int maxn = 1e6 + 7;
const ll linf = 1e9 + 7;
ll n, q, m, a[maxn], stepen;
int main(){
    cin >> n >> q >> m;
    for(ll i = 1; i <= n; i++){
        cin >> a[i];
    }
    for(ll i = q; i <= n; i++){
        if(a[i] > 0)
            if(a[i] <= m){
                stepen = i - q;
                break;
            }
    }
    for(ll i = q; i >= 1; i--){
        if(a[i] > 0)
            if(a[i] <= m){
                stepen = min(i - q, stepen);
                break;
            }
    }
    cout << llabs(stepen) * 10;
    return 0;
}

#include <iostream>

using namespace std;
int v[101];
int main()
{
    int n,m,k,st,dr,i;
    cin>>n>>m>>k;
    st=m;
    dr=m;
    for (i=1; i<=n; i++)
    {
        cin>>v[i];
    }
    for (i=1; i<=max(m,n-m); i++)
    {
        if (v[st-i]!=0&&v[st-i]<=k)
        {
            cout<<i*10;
            break;
        }
        if (v[dr+i]!=0&&v[dr+i]<=k)
        {
            cout<<i*10;
            break;
        }
    }
    return 0;
}

#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int n,m,k,i;
int a[100001];
int ans=99999999,ans1=99999999;
main(){
	cin>>n>>m>>k;
	for(i=0;i<n;i++)
	cin>>a[i];
	for(i=m-1;i>0;i--)
	if(a[i]>0 && a[i]<k){
		ans=(m-i-1)*10;
		break;
	}
	for(i=m+1;i<n;i++)
	if(a[i]>0 && a[i]<k){
		ans1=(i-m+1)*10;
		break;
	}
	cout<<min(ans,ans1);
}

#include <iostream>

#include<algorithm>

#include<math.h>

using namespace std;

int n, m, k, a[100],i, ans=INT_MAX;

int main()
{
    cin>>n>>m>>k;
    for(i=1;i<=n;i++)
    {
        cin>>a[i];
        if(a[i]!=0 && a[i]<=k)
        {
            if(fabs(i-m)<ans)
            {
                ans=abs(i-m);
            }
        }

    }
    cout<<ans*10;

return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,m,k,i,j,p,q,cnt=1,cnt1=1,h,res;
    scanf("%d %d %d",&n,&m,&k);
    int arr[10000];
    p=m+1;
    q=m-1;
    for(i=1;i<=n;i++)
    {
        scanf("%d",&arr[i]);
    }
    while(p<=n)
    {
    if(arr[p]!=0 && arr[p]<=k)
        {
         printf("%d",cnt);
         break;
        }
     else
            cnt++;
            p++;
    }
     while(q>0)
    {
    if(arr[q]!=0 && arr[q]<=k)
        {
         printf("%d",cnt);
         break;
        }
     else
            cnt1++;
            q--;
    }

h=min(cnt,cnt1);
printf("%d",h*10);

return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    long long n,m,k;
    cin>>n>>m>>k;

    long long a[n];

    for (long long i=0;i<n;i++)
    {
        cin>>a[i];
    }

    long long ans,res;

    for (long long i=m-1;i>=0;i--)
    {
        if (a[i]!=0 and a[i]<=k)
        {
            ans=i;
            break;
        }
    }

    for (long long i=m;i<n;i++)
    {
        if (a[i]!=0 and a[i]<=k)
        {
            res=i;
            break;
        }
    }

    long long x=abs(m-1-ans);
    long long y=abs(m-1-res);

    cout<<min(x,y)*10;
    return 0;
}

        #include <stdio.h>
        #include<iostream>
        #include<string.h>
        #include<algorithm>
        #include<functional>
        #include<vector>
        #include<cmath>
        #include<numeric>
        #include<iomanip>
        #include<queue>
        #include<string>
        using namespace std;
        int main()
        {
        	int n,m,k;
        	cin>>n>>m>>k;
        	int a[105];
        	for(int i=0;i<n;++i)
        	{
        		cin>>a[i];
        	}
        	int s1=2000,s2=2000;
        	for(int i=m+1;i<=n;++i)
        	{
        		if(a[i]<=k&&a[i]!=0)
        		{
        			s1=10*(i-m);
        			break;
        		}
        	}
        	for(int i=m-1;i>=1;i--)
        	{
        		if(a[i]<=k&&a[i]!=0)
        		{
        			s2=10*(m-i-1);
        			break;
        		}
        	}
        	if(s2<s1)
        	cout<<s2;
        	else cout<<s1;
            return 0;
        }

#include<bits/stdc++.h>
using namespace std;
int a[1000],k;
int ans(int s,int n) {
    int sum=10;
    for(int i=s+1; i<=n; i++) {
        if(a[i]!=0&&a[i]<=k)
            return sum;
        sum+=10;
    }
    return sum;
}
int main() {
    int n,m,i;
    scanf("%d %d %d",&n,&m,&k);
    for(i=1; i<=n; i++) {
        scanf("%d",&a[i]);
    }
    int x,sum=10;
    x=ans(m,n);
    //cout<<x<<endl;
    for(i=m-1; i>=1; i--) {
        if(a[i]!=0&&a[i]<=k)
            break;
        sum+=10;
    }
    if(i==m-1)
        printf("%d",x);
    else
        printf("%d",min(x,sum));
}

#include <iostream>
#include <string.h>
#include <set>
#include <vector>
#include <queue>
#include <cmath>
#include <math.h>
#include <algorithm>
#include <map>
#include <stack>
#include <iomanip>
#include <functional>
using namespace std;
#define ll long long int
#define rep(i,n) for(ll i=0;i<n;i++)
#define rep2(i,n) for(ll i=1;i<n;i++)
#define N 100000
//done?????
int main()
{
    ll n,m,k;
    cin>>n>>m>>k;
    ll a[n];
    rep(i, n)
    cin>>a[i];
    ll t=-1;
    rep(i,m)
    {
        if(a[i]<k&&a[i]!=0)
            t=i;
    }
    ll z=-1;
    for(ll i=m;i<n;i++)
    {
        if(a[i]!=0&&a[i]<k)
        {
            z=i;
            break;
        }
    }
    if((z-m+1<t&&z!=-1)||t==-1)
    {
        cout<<10*(z-m+1)<<" ";
    }
    else
        cout<<10*(m-t-1)<<" ";
}

#include <iostream>
#include <string>
#include <cstring>
#include <cctype>

using namespace std;

int main() {
	int n, m, k;
	cin >> n >> m >> k;

	int *house_price = new int[n];

	for (int i = 0; i < n; i++) {
		cin >> house_price[i];
	}

	bool*available = new bool[n] {0};
	int *distance_of_house = new int[n];
	int min_distance=n;

	for (int i = 0; i < n; i++) {
		if (house_price[i] != 0) {
			available[i] = true;
		}
	}

	for (int i = 0; i < n; i++) {
		if (available[i]==true && house_price[i]<k) {
			distance_of_house[i] = abs((m - 1) - i);
		}
	}

	for (int i = 0; i < n; i++) {
		if (distance_of_house[i] > 0) {
			if (distance_of_house[i] < min_distance)
				min_distance = distance_of_house[i];
		}
	}

	cout << min_distance * 10 << endl;

	//system("pause");
	return 0;
}

#include<bits/stdc++.h>

using namespace std;

#define NN 111

#define rep(i,a,b) for(i=a;i<b;i++)

int a[NN];

int main(){

	int n,m,k,i;

	cin>>n>>m>>k;

	rep(i,1,n+1) cin>>a[i];

	for(i=1;;i++){

		int u=m-i,v=m+i;

		if(u>=0&&a[u]!=0&&a[u]<k) break;

		if(v<=n&&a[v]!=0&&a[v]<k) break;

	}

	cout<<i*10;

	return 0;

}

#include <bits/stdc++.h>

using namespace std;

int main() {

	int n, m, k;
	cin >> n >> m >> k;
	int houseValues[n];
	int minDistance = (n * 10);
	for (int i = 0; i < n; i++) {
		cin >> houseValues[i];
		if (m = i + 1)
			continue;
		if (houseValues[i] > 0 && houseValues[i] <=k)
			minDistance = min(minDistance, abs(10 * (m - (i+1))));
	}

	cout << minDistance << endl;
	return 0;
}

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <limits>
#include <cmath>
#include <functional>
#include <list>
#include <numeric>

using namespace std;

#define ll	long long
#define ld	long double
#define vi	vector<int>
#define rep(i,a,b)	for(int i=a;i<b;i++)

ll pow2(ll a, ll b)
{
	if (b == 0)
		return 1;
	if (b == 1)
		return a;
	if (b % 2 == 1)
		return pow2(a, b / 2)*pow2(a, b / 2)*a;
	else
		return pow2(a, b / 2)*pow2(a, b / 2);
}

int CC(int x, int y) {
	ll ans = 1;
	vi ys(y - 1);
	iota(ys.begin(), ys.end(), 2);
	int y_ind = 0;
	//	for (int i = x + y; i > x; i--) {
	for (int i = x + 1; i < x + y + 1; i++) {
		ans *= i;
		if (y_ind < y - 1 && ans % ys[y_ind] == 0) {
			ans /= ys[y_ind++];
		}
		if (y_ind == y - 1 && ans >1000000007)
			ans %= 1000000007;
	}
	if (ans > 1000000007)
		ans %= 1000000007;

	return ans;
}

int main()
{
	int n, m, k;
	cin >> n >> m >> k;
	vi a(n);
	rep(i, 0, n)
		cin >> a[i];

	int ans=-1;
	rep(i, m, n) {
		if (a[i] <= k && a[i]!=0) {
			ans = i;
			break;
		}
	}
	for (int i = m - 2; i >= 0; i--) {
		if (a[i] <= k && a[i]!=0) {
			ans = min(i,ans);
			break;
		}
	}

	cout << abs(ans - m + 1) * 10 << endl;
	return 0;
}

#include <iostream>
using namespace std;
int n,m,k,t,a,b,i,j;
int arr[100];
int main () {
    cin>>n>>m>>k;
    for (i=1;i<=n;i++) {
        cin>>a;
        arr[i]=a;
    }
    b=10000;
    for (i=m;i>=0;i--) {
        if (arr[i]!=0 && arr[i]<=k) {b=i;break;}
    }
    j=10000;
    for (i=m;i<=n;i++) {
        if (arr[i]!=0 && arr[i]<=k) {j=i;break;}
    }
    if ((m-b)<(j-m)) cout<<(m-b)*10<<endl;
    else
    cout<<(j-m)*10<<endl;
    return 0;
}

#include <iostream>

using namespace std;

int main()
{
int a[105];
int n,m,k;
cin>>n>>m>>k;
for(int i=1;i<=n;i++)cin>>a[i];

int h=0,l=0;
for(int  i=m+1;i<=n;i++)
{
    if(a[i]<=k && a[i]!=0)
    {
        h++;
        break;

    }
    else{
        h++;

    }
}
for(int i=m-1;i>=1;i--)
{
    if(a[i]<=k && a[i]!=0)
    {
        l++;
        break;

    }
    else{
        l++;

}
}
l=l*10;
h=h*10;

if(l!=0 && m!=0)
{
    cout<<min(l,h)<<endl;
}
else if(l==0)cout<<m<<endl;
else if(m==0)cout<<l<<endl;

   return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n,m,k;
	cin>>n>>m>>k;
	int ar[n+5];
	for(int i=1;i<=n;i++)
	{
		cin>>ar[i];
	}
	for(int i=1;i<=n;i++)
	{
		if(ar[m-i]<=k and ar[m-i]>0)
		{
			cout<<i*10;
			return 0;
		}
		else if(ar[m+i]<=k and ar[m+i]>0)
		{
			cout<<i*10;
			return 0;
		}
	}
}

#include<iostream>
using namespace std;
bool Error=true;
int main (){

    int Search[101] , Data1 , Data2 , Data3  , Trap=0 , min_virus;
    cin >> Data1 >> Data2 >> Data3 ;
    for(int i=0 ; i<Data1 ; i++)
    {
        cin >> Search[i];
        if(i+1==Data2)
            if(Search[i]==0)Error=false;
        if(Error==false)
        {
            if(Search[i]!=0)
            {
                Data2=i+1;
                Error=true;
            }
        }

    }
	for(int i=Data2-1 ; i<Data1 ; i++)
	{
	    if(i==Data2-1)min_virus=Search[i];
		else min_virus=min(Search[i] , min_virus);
	}
    for(int i=Data2-1 ; i<Data1 ; i++)
    {
        Trap+=10;
        if(Search[i]<=Data3 && Search[i]<min_virus)
        {
            cout << Trap;
            return 0;
        }
    }
	cout << Trap;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main(){
    int n, m, k;
    cin >> n >> m >> k;
    m--;
    vector<int> a(n);
    for (int i = 0; i < n; i++)
        cin >> a[i];

    int res = 101;
    for (int i = n - 1; i > m; i--)
        if (a[i] != 0 && a[i] <= k)
            res = (i - m) * 10;

    for (int i = 0; i < m; i++)
        if (a[i] != 0 && a[i] <= k && res > (m - i) * 10)
            res = (m - i) * 10;

    cout << res;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main() {
	int n , k , m,j,i,p=0;
	cin>>n>>m>>k;
	vector<int> T(n);
	for(int i =0 ; i<n  ;i++) cin>>T[i];
	for(i=m;i<n && p==0;i++){
		if(T[i]==0)
			continue;
		else if(T[i]<=k)
				p=1;

	}
	p=0;
	for( j=m-1;j>=0 && p==0;j--){
			if(T[j]==0)
				continue;
			else if(T[j]<=k)
				p=1;
		}
	if(j<i && j>0)
		cout << ((m-j-2)*10 )<<endl;
	else cout <<((i-m)*10)<<endl;
	return 0;
}

#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int n,m,k,i;
int a[100001];
int ans=99999999,ans1=99999999;
main(){
	cin>>n>>m>>k;
	for(i=0;i<n;i++)
	cin>>a[i];
	for(i=m-1;i>=0;i--)
	if(a[i]>0 && a[i]<=k){
		ans=(m-i-1)*10;
		break;
	}
	for(i=m+1;i<n;i++)
	if(a[i]>0 && a[i]<=k){
		ans1=(i-m+1)*10;
		break;
	}
	cout<<min(ans,ans1);
}

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int main(){
    int n,m,k,w,e;
    cin >>n>>m>>k ;
    int min_costright,min_costleft,min_cost;
    int a[n];
    for (int i =0;i<n;i++){
    	cin>> a[i];
    }
  //  cout << "m"<<m<<endl;
    for (w = m;w<n;w++){
    	if(a[w]!=0){
    	if(a[w]<=k){
    		min_costright = a[w];
    		break;
    	}
    }

    }
 //  cout<<"w"<<w-m+1<<endl;
    if(m>1){
    for(e = m-2;e>=0;--e){
    	if(a[e]!=0){
    	if(a[e]<k){
    		min_costleft = a[e];
    		break;
    	}
    }
    }
    if(e<0){
    	e=-10000;
    }
}
   // cout<<"e1"<<m-e+1<<endl;
    if(m>1){
    	if(m-e-1<w-m+1){
    		cout<<10*(m-e-1);
    	}
    	else cout<<10*(w-m+1);
    }
    else cout<<10*(w-m+1);
 //  cout<<"e"<<m-e<<"w"<<w-m<<endl;

   // cout<<min_cost;

    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n,m,k;
	cin>>n>>m>>k;
	int ar[n+1];
	for(int i=1;i<=n;i++)
	{
		cin>>ar[i];
	}
	for(int i=1;i<=n;i++)
	{
		if(ar[m-i]<=k and ar[m-i]>0)
		{
			cout<<i*10;
			return 0;
		}
		else if(ar[m+i]<=k and ar[m+i]>0)
		{
			cout<<i*10;
			return 0;
		}
	}
}

	#include <iostream>
	#include <algorithm>
	#include <string>
	#include <cmath>
	#include "stdlib.h"
	#include <stdio.h>
	#include <fstream>

	#pragma warning(disable : 4996)
	using namespace std;

	int main()
	{

		int n,m,k,a=0,b=0,fla=0,flb=0;
		cin >>n>>m>>k;
		int *x = new int[n];
		for (int i = 0; i < n; i++) {
		cin >> x[i];
		}
		if (m == 1) {
			a = 10;
			for (int i = 1; i <n; i++) {
				if (x[i] > 0 && x[i]>k)
					a += 10;
				else if (x[i] == 0)
					a += 10;
				else
					break;
			}
			cout << a;
		}
		else if (m == n) {
			a = 10;
			for (int i = m - 2; i >= 0; i--) {
				if (x[i] > 0 && x[i]>k)
					a += 10;
				else if (x[i] == 0)
					a += 10;
				else
					break;
			}
			cout << a;
		}
		else {
			a = 10;
			for (int i = m - 2; i >= 0; i--) {
				if (x[i] > 0 && x[i] > k) {
					a += 10;
					fla = 1;
				}
				else if (x[i] == 0)
					a += 10;
				else {
					fla = 1;
					break;
				}
			}
			b = 10;
			for (int i = m; i <n; i++) {
				if (x[i] > 0 && x[i] > k) {
					b += 10;
					flb = 1;
				}
				else if (x[i] == 0)
					b += 10;
				else {
					flb = 1;
					break;
				}
			}
			if (a > b &&flb==1)
				cout << b;
			else if (a > b &&flb == 0)
				cout << a;
			else if (a < b &&fla == 1)
				cout << a;
			else if (a < b &&fla == 0)
				cout << b;
			else
				cout << a;
		}

		return 0;
	}

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n,m,k;
    cin>>n>>m>>k;
    int ar[n];
    for(int i=0;i<n;i++)
    {
        cin>>ar[i];
    }
    int cn1=0,cn2=0;
    for(int i=m-1;i<n;i++)
    {
        if(ar[i]!=0 && ar[i]<=k)
        {
            cn1=i;
            break;
        }
    }
    for(int i=m-1;i>=0;i--)
    {
        if(ar[i]!=0 && ar[i]<=k)
        {
            cn2=i;
            break;
        }
    }

    if(cn1==0)
    cout<<abs(10*(cn2-m+1));
   else if(cn2==0)
    cout<<abs(10*(m-cn1-1));
    else
    cout<<abs(10*min(cn1,cn2));
    return 0;
}

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main ()
{
    int n,f,l,mini=999999;
    cin>>n>>f;
    int k[n];
    vector <int> h;
    for (int i=0;i<n;i++)
    cin>>k[i];
    for (int i=0;i<n;i++)
    if(k[i]<=l&&k[i]!=0)
    h.push_back(i);
    for (int i=0;i<h.size();i++)
    if(h[i]<f)
    mini=min(mini,f-h[i]);
    else mini=min(mini,h[i]-f);
    cout <<mini*10+10;
    return 0;
}

#include<iostream>
#include<fstream>
#include<cmath>
#include<string>
#include<set>
#include <map>
#include<algorithm>
#include<vector>
#include <queue>
using namespace std;
typedef long long ll ;

int main()
{
	int a , b , dol , arr[101];
	cin >> a >> b >> dol ;
	for(int i=0;i<a;i++)
	{
		cin >> arr[i];
	}
	int m1=1000000 , m2=1000000 , m ;
	for(int i=b+1;i<=a;i++)
	{
		if(arr[i] <= dol &&arr[i]!=0){
			m1 = i ;
			break;
		}
	}

	for(int i=b+1;i>0;i--)
	{
		if(arr[i] <= dol&arr[i]!=0){
			m2 = i ;
			break;
		}
	}

	if(abs(m1-b) <= abs(m2-b))
		cout << abs(m1-b+1) *10;
	else
		cout << abs(m2-b+1) *10;

		return 0;
}

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <limits>
#include <cmath>
#include <functional>
#include <list>
#include <numeric>

using namespace std;

#define ll	long long
#define ld	long double
#define vi	vector<int>
#define rep(i,a,b)	for(int i=a;i<b;i++)

ll pow2(ll a, ll b)
{
	if (b == 0)
		return 1;
	if (b == 1)
		return a;
	if (b % 2 == 1)
		return pow2(a, b / 2)*pow2(a, b / 2)*a;
	else
		return pow2(a, b / 2)*pow2(a, b / 2);
}

int CC(int x, int y) {
	ll ans = 1;
	vi ys(y - 1);
	iota(ys.begin(), ys.end(), 2);
	int y_ind = 0;
	//	for (int i = x + y; i > x; i--) {
	for (int i = x + 1; i < x + y + 1; i++) {
		ans *= i;
		if (y_ind < y - 1 && ans % ys[y_ind] == 0) {
			ans /= ys[y_ind++];
		}
		if (y_ind == y - 1 && ans >1000000007)
			ans %= 1000000007;
	}
	if (ans > 1000000007)
		ans %= 1000000007;

	return ans;
}

int main()
{
	int n, m, k;
	cin >> n >> m >> k;
	m--;
	vi a(n);
	rep(i, 0, n)
		cin >> a[i];

	int ans=numeric_limits<int>::max();
	rep(i, m + 1, n) {
		if (a[i] <= k && a[i]!=0) {
			ans = i;
			break;
		}
	}
	for (int i = m - 2; i >= 0; i--) {
		if (a[i] <= k && a[i]!=0) {
			ans = min(i,ans);
			break;
		}
	}

	cout << abs(ans - m + 1) * 10 << endl;
	return 0;
}

/*Simanta Deb Turja's Template*/

#include <bits/stdc++.h>

//MACROS
#define repB(i, a, b) for(i = b; i < a; i++)
#define rep0(i, a) for(i = 0; i < a; i++)
#define reprev(i, a, b) for(i = b; i >= a; i--)
#define tcLoop(i, a) for(i = 1; i <= a; i++)

//Constant Values
#define MAX 1000007

typedef unsigned long long ull;
typedef long long ll;

using namespace std;

int main()
{
  //freopen("input.txt", "r", stdin);
  //freopen("output.txt", "a", stdout);
  ios_base :: sync_with_stdio(false);
  //cin.tie(NULL);
  int n, m, k;
  while(cin >> n >> m >> k) {
    int arr[101];
    int maximumP = 10;
    int maximumN = 10;
    int maximumA = 10;
    int mark1;
    int mark2;
    int mark3;

    for(int i = 1; i <= n; i++) {
      cin >> arr[i];
    }

    if(m == 1) {
      for(int i = m + 1; i <= n; i++) {
        if(arr[i] <= k && arr[i] != 0) {
          mark1 = i;
          break;
        }
      }
      cout << maximumA * (mark1 - 1) << endl;
    }
    else if(m == n) {
      for(int i = m - 1; i >= 1; i--) {
        if(arr[i] <= k && arr[i] != 0) {
          mark1 = i;
          break;
        }
      }
      cout << maximumA * (mark1 - 1) << endl;
    }
    else if(m > 1 && m != 1 && m!=n) {
      for(int i = m - 1; i >= 1; i--) {
        if(arr[i] <= k && arr[i] != 0) {
          mark2 = i;
          break;
        }
      }
      for(int i = m + 1; i <= n; i++) {
        if(arr[i] <= k && arr[i] != 0) {
          mark3 = i;
          break;
        }
      }
      maximumN = maximumN * (m - mark2);
      maximumP = maximumP * (mark3 - m);
      //cout << "P: " << maximumP << endl;
      //cout << "N: " <<maximumN << endl;
      int ans = min(maximumP, maximumN);
      cout << ans << endl;
    }

  }

  return 0;
}

#include <iostream>
#include <vector>
#include <stdio.h>
using namespace std;

int main() {
	int money, H, n;
	int i,j;
	cin >> n >> H >> money;
	vector<int> vec(n);
	H--;
	for(int i=0; i<n; i++)
		cin >> vec[i];
	i=1;
	do
	{
		if((vec[H+i]!=0&&vec[H+i]<money)||(vec[H-i]!=0&&vec[H-i]<money))
			break;
		i++;
	}while(1);
	printf("i=%d", i*10);
	return 0;
}

#include<bits/stdc++.h>
using namespace std;

int main(){
    int n,m,k,t;
    vector<int> v;
    cin >> n >> m >> k;
    for(int i=0;i<n;i++){
        cin >> t;
        v.push_back(t);
    }
    int ans,f,b;
    for(int i=m+1;i<n;i++){
        if(v[i] && v[i]<=k){
            f=i+1;
            break;
        }
    }
    int temp = f-m;
    for(int i=m-1;i>=0;i--){
        if(v[i] && v[i]<=k){
            b=i+1;
            if(m-b < temp){
                temp = m-b;
                break;
            }
            break;
        }
    }
    ans = temp*10;
    cout << ans << endl;
    return 0;
}

#include<iostream>
#include<bits/stdc++.h>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cstring>

using namespace std;

int main()
{
	int n,m,k,before=0,after=0;
	cin>>n>>m>>k;

	int a[n];

	for(int i=0;i<n;i++)
	{
		cin>>a[i];
	}

	for(int i=m-1;i>=0;i--)
	{
		if(a[i]<=k && a[i]>0)
		{
			before=i+1;
			break;
		}
	}
	for(int i=m;i<n;i++)
	{
		if(a[i]<=k && a[i]>0)
		{
			after=i+1;
			break;
		}
	}

	if(m==1)
		cout<<10*(after-m)<<"\n";
	else if(m==n)
		cout<<10*(m-before)<<"\n";
	else
		cout<<min(10*(abs(m-before)),10*(abs(after-m)))<<"\n";

	// cout<<"before="<<before<<"\n";
	// cout<<"after="<<after<<"\n";

	return 0;
}

#include<bits/stdc++.h>
using namespace std;
#define f(i,a,b) for(int(i)=int(a);i<=int(b);i++)
#define ff(i,a,b) for(int(i)=int(a);i<int(b);i++)
#define F(i,a,b) for(int(i)=int(a);i>=int(b);i--)
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;
int main(){
	int n,m,k,current=0;
	cin>>n>>m>>k;
	int a[n+1];
	f(i,1,n) cin>>a[i];
	f(i,1,n){
		if(i!=m){
			if(k>=a[i]){
				current=max(current,abs(m-i)*10);
			}
		}
	}
	cout<<current;
}

#include<iostream>
#include<cmath>
using namespace std;
main()
{int n,m,k,pos1=0,pos2=0;
cin>>n>>m>>k;
int *a=new int[n];
for(int i=1;i<=n;i++)
cin>>a[i];

for(int i=m;i>=1;i++)
{if(a[i]!=0&&a[i]<=k)
    {pos1=i;
    break;
    }
}
for(int i=m;i<=n;i--)
{
if(a[i]!=0&&a[i]<=k)
    {pos2=i;
    break;
    }

}

if(fabs(m-pos1)<=fabs(m-pos2)&&fabs(m-pos1)!=0)

cout<<10*(fabs(pos1-m));

else if(fabs(m-pos1)>fabs(m-pos2))

cout<<10*(fabs(pos2-m));
else cout<<10*(fabs(pos2-m));
}

#include<iostream>
#include<string>
#include<vector>
#include<stack>
#include<algorithm>
#include<iomanip>
#include<cmath>
using namespace std;

int main()
{
	int n, m, k;
	cin >> n >> m >> k;
	int l=0, r=0;
	bool lo = false, ro = false;
	int *price = new int[5]();
	for (int i = 0; i < n; i++)
		cin >> price[i];
	for (int i = m-1; i >= 0; i--)
	{
		if (k<price[i] || price[i] == 0)
		{
			l++;
			continue;
		}
		else{
			lo = true;
			break;
		}
	}
	for (int i = m + 1; i < n; i++)
	{
		if (k<price[i] || price[i] == 0)
		{
			r++;
			continue;
		}
		else{
			ro = true;
			break;
		}
	}
	int r1=999999, l1=999999;
	if (ro)
		r1 = 10 * r;
	if (lo)
		l1 = 10 * l;
	int result = r1 < l1 ? r1 : l1;
	cout << result << endl;
	return 0;
}

#include<iostream>
#include<algorithm>
#include<math.h>
#include<vector>
#include<map>
#include<list>
#include<iterator>
long long int a[100000];
using namespace std;
typedef long long int ll;
int main()
{
    ll i,j,n,t,m,k,p=0,p1=0,p2;
    map<ll,ll>m1;
    map<ll,ll>::iterator it;
    vector<ll > v;
    list<ll>l;
    string s1;
    cin>>n>>m>>k;
    for(i=0; i<n; i++)
    {
        cin>>j;
        v.push_back(j);
    }
    for(i=m-1; i<n; i++)
    {
        if(v[i]<=k&&v[i]!=0)
        {
            p=i+1;
            break;
        }
    }
    for(i=m-1; i>=0; i--)
    {
        if(v[i]<=k&&v[i]!=0)
        {
            p1=i+1;
            break;
        }
    }
    p2=p1;
    if(p1>0)
        p1=m-p1;
    //cout<<p<<p1<<endl;
    if(p>0&&p1>0)
    j=min(p,p1);
    else
    {
        if(p>0)
            j=p-m;
        else
            j=m-p2;
    }
    cout<<(j*10)<<endl;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,m,k,temp1,result=0,temp2;
	cin>>n>>m>>k;
	int a[n+1];
	for(int i=1;i<n+1;i++)
		cin>>a[i];
	if(m>1)
	{
		temp1=m-1;
		while(temp1>=1)
		{
			if(a[temp1]==0 || a[temp1]>k)
				temp1--;
			else break;
		}
		if(a[temp1]!=0 && temp1!=0)
		{
		result=abs(temp1-m);
		}
	}
	//cout<<"result1->"<<result<<endl;
	if(m<=n-1)
	{
		//cout<<"hiii"<<endl;
		temp2=m+1;
		while(temp2<n)
		{
//			cout<<"hiii"<<endl;
			if(a[temp2]==0 || a[temp2]>k)
				temp2++;
			else break;
			cout<<temp2<<" ";
		}
		cout<<endl;
		if(result!=0 && a[temp2]!=0)
		result=min(result,abs(temp2-m));
		else
			result=abs(temp2-m);
	}
	//cout<<"result2->"<<result<<endl;
	result=result*10;
	cout<<result<<endl;
	return 0;
}

#include <iostream>
#include <vector>
#include <math.h>
using namespace std;

int main()
{
	std::ios::sync_with_stdio(false);

	int n, m, k;
	cin >> n >> m >> k;

	vector<int> houses(n);
	for (int i = 0; i < n; cin >> houses[i++]);

	int l;
	for (l = m - 1; l >= 0; l--)
	{
		if (houses[l] == 0 || houses[l] > k) continue;
		if (houses[l] <= k) break;
	}
	int stepL = (l < 0) ? 0 : abs(l - (m - 1));

	int r;
	for (r = m - 1; r <= n - 1; r++)
	{
		if (houses[r] == 0 || houses[r] > k) continue;
		if (houses[r] <= k) break;
	}
	int stepR = (r > n - 1) ? 0 : abs(r - (m - 1));
	if (stepL == 0 || stepR < stepL)
		cout << stepR * 10 << endl;
	else if (stepR == 0 || stepL < stepR)
		cout << stepL * 10 << endl;

	//system("pause");
	return 0;
}

#include<bits/stdc++.h>
using namespace std;

int main()  {

    int pos1,pos2,v[200],n,m,k,i,x;

    cin >> n >> m >> k;
    for( i=1 ; i<= n ; i++)  cin >> v[i];

    for( i=1 ; i<= n ; i++) {
        if( v[i] > 0 && v[i] <= k) {
          pos1 = i;
          break;
        }
        else continue;
    }

    for( i=m ; i>0 ; i--) {
        if( v[i] > 0 && v[i] <= k) {
          pos2 = i;
          break;
        }
        else  continue;
    }

    int p =  abs( pos1-m ) * 10;
    int q =  abs( pos2-m ) * 10;
    if( q==0 ) cout << p;
    else cout << min(p,q);
        return 0;
}

#include <bits/stdc++.h>

using namespace std;

int main(){
    int n, m, k, o, mod, min;
    cin >> n >> m >> k;
    vector <int> a;
    a.reserve(n);
    vector <int> r(n);
    vector <int> index(n);

    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }
    for(int i = 0; i < n; i++) {
        if(a[i] == 0) index[i] = 1;
    }
    index[m-1] = 2;
    for(int i = 0; i < n; i++) {
        if((index[i] == 0) && (a[i] <= k)) index[i] = 3;
    }
    min = 1000;
    for(int i = 0; i < n; i++) {
        mod = i - (m-1);
        mod = abs(mod);
        if((index[i] == 3) && (r[i] < mod)) {
            r[i] = i;
        }
    }
    sort(r.begin(), r.end());
    for(int i = 0; i < n; i++) {
        if(r[i] > 0) {
            min = r[i];
            break;
        }
    }
    o = (min - (m - 1)) * 10;
    if(o < 0) o *= -1;
    cout << o;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int i,j=0,n,m,k,a[100],b[100],c=0,d=0,l,a1,f,c1,min1;

    cin>>n>>m>>k;

    for(i=1; i<=n; i++)
    {
        cin>>a1;

        if(a1<=k && a1>0)
        {
            f=min(f,abs(i-m)*10);

        }

    }

    cout<<f<<endl;
    return 0;

}