#include <bits/stdc++.h>

using namespace std;

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

#define pb push_back
#define mp make_pair

int n, t;
string s1, s2;

int main()
{
    ios_base::sync_with_stdio(0);
    cin >> n >> t >> s1 >> s2;
    int cur = 0;
    string ans;
    ans.resize(n);
    for(int i = 0; i < n; i++){
        if(s1[i] != s2[i]) cur++;
    }
    if(t < cur){
        cout << -1 << endl;
        exit(0);
    }
    for(int i = 0; i < n && t > 0; i++){
        if(s1[i] != s2[i]){
            for(int j = 'a'; j <= 'z'; j++){
                if(s1[i] != j && s2[i] != j){
                    ans[i] = j;
                    break;
                }
            }
            t--;
        }
    }

    for(int i = 0; i < n; i++){
        if(s1[i] == s2[i]){
            if(t > 0){
                if(s1[i] == 'a') ans[i] = 'b';
                else ans[i] = 'a';
                t--;
            }
            else ans[i] = s1[i];
        }
    }

    cout << ans;

    return 0;
}


#include <bits/stdc++.h>

using namespace std;

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

#define pb push_back
#define mp make_pair

int n, t;
string s1, s2;

int main()
{
    ios_base::sync_with_stdio(0);
    cin >> n >> t >> s1 >> s2;
    int cur = 0;
    string ans;
    ans.resize(n);
    for(int i = 0; i < n; i++){
        if(s1[i] != s2[i]) cur++;
    }
    if(t < cur){
        cout << -1 << endl;
        exit(0);
    }
    for(int i = 0; i < n && t > 0; i++){
        if(s1[i] != s2[i]){
            if(s1[i] != 'a' && s2[i] != 'a') ans[i] = 'a';
            else if(s1[i] != 'b' && s2[i] != 'b') ans[i] = 'b';
            else ans[i] = 'c';
            t--;
        }
    }

    for(int i = 0; i < n; i++){
        if(s1[i] == s2[i]){
            if(t > 0){
                if(s1[i] == 'a') ans[i] = 'b';
                else ans[i] = 'a';
            }
            else ans[i] = s1[i];
        }
    }

    cout << ans;

    return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  if (t == 0) {
    if (s1 != s2) {
      cout << -1;
      return 0;
    }
    cout << s1;
    return 0;
  }

  set<char> f, s, both, fr;
  for (auto &c : s1) f.emplace(c);
  for (auto &c : s2) s.emplace(c);
  for (auto &c : f) {
    if (s.count(c)) both.emplace(c);
  }
  for (char i = 'a'; i <= 'z'; i++) fr.emplace(i);
  for (auto &c : s1) fr.erase(c);
  for (auto &c : s2) fr.erase(c);

  string ans(n, '0');
  int p = 0;
  for (int i = 0; i < n - t; i++) {
    if (!both.empty()) {
      ans[i] = *both.begin();
    } else {
      if (p) {
        if (f.empty()) {
          cout << -1;
          return 0;
        }
        ans[i] = *f.begin();
      } else {
        if (s.empty()) {
          cout << -1;
          return 0;
        }
        ans[i] = *s.begin();
      }
      p ^= 1;
    }
    both.erase(ans[i]);
    f.erase(ans[i]);
    s.erase(ans[i]);
  }

  for (int i = n - t; i < n; i++) {
    if (fr.empty()) {
      cout << -1;
      return 0;
    }
    ans[i] = *fr.begin();
    fr.erase(ans[i]);
  }

  cout << ans;
  return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  int eq = 0, neq = 0;
  for (int i = 0; i < n; i++) {
    if (s1[i] != s2[i]) neq++;
    else eq++;
  }

  int eqq = n - t;
  if (neq < 2 * (eqq - eq)) {
    cout << -1;
    return 0;
  }

  set<char> fr;
  for (int c = 'a'; c <= 'z'; c++) {
    fr.emplace(c);
  }

  string ans(n, '0');
  int j = 0;
  for (int i = 0; i < n && j < eqq; i++) {
    if (s1[i] == s2[i]) {
      ans[i] = s1[i];
      j++;
    }
  }

  for (int i = 0; i < n && j < 2 * (eqq - t); i++) {
    if (s1[i] == s2[i]) continue;
    j++;
    ans[i] = (j & 1 ? s1[i] : s2[i]);
  }

  for (int i = 0; i < n; i++) {
    if (ans[i] == '0') {
      fr.erase(s1[i]);
      fr.erase(s2[i]);
      ans[i] = *fr.begin();
      fr.emplace(s1[i]);
      fr.emplace(s2[i]);

    }
  }

  cout << ans;
  return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  int eq = 0, neq = 0;
  for (int i = 0; i < n; i++) {
    if (s1[i] != s2[i]) neq++;
    else eq++;
  }

  int eqq = n - t;
  if (neq < 2 * (eqq - eq)) {
    cout << -1;
    return 0;
  }

  set<char> fr;
  for (int c = 'a'; c <= 'z'; c++) {
    fr.emplace(c);
  }

  string ans(n, '0');
  for (int i = 0; i < n && eqq; i++) {
    if (s1[i] == s2[i]) {
      ans[i] = s1[i];
      eqq--;
    }
  }

  int tmp = 2 * eqq;
  for (int i = 0; i < n && tmp; i++) {
    if (s1[i] == s2[i]) continue;
    tmp--;
    ans[i] = (tmp & 1 ? s1[i] : s2[i]);
  }

  for (int i = 0; i < n; i++) {
    if (ans[i] == '0') {
      fr.erase(s1[i]);
      fr.erase(s2[i]);
      ans[i] = *fr.begin();
      fr.emplace(s1[i]);
      fr.emplace(s2[i]);

    }
  }

  cout << ans;
  return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  int eq = 0, neq = 0;
  for (int i = 0; i < n; i++) {
    if (s1[i] != s2[i]) neq++;
    else eq++;
  }

  int eqq = n - t;
  if (neq < 2 * (eqq - t)) {
    cout << -1;
    return 0;
  }

  set<char> fr;
  for (int c = 'a'; c <= 'z'; c++) {
    fr.emplace(c);
  }
  for (auto &c : s1) fr.erase(c);
  for (auto &c : s2) fr.erase(c);

  string ans(n, '0');
  int j = 0;
  for (int i = 0; i < n && j < eqq; i++) {
    if (s1[i] == s2[i]) {
      ans[i] = s1[i];
      j++;
    }
  }

  for (int i = 0; i < n && j < 2 * (eqq - t); i++) {
    if (s1[i] == s2[i]) continue;
    j++;
    ans[i] = (j & 1 ? s1[i] : s2[i]);
  }

  for (int i = 0; i < n; i++) {
    if (ans[i] == '0') {
      if (fr.empty()) {
        cout << -1;
        return 0;
      }
      ans[i] = *fr.begin();
      fr.erase(ans[i]);
    }
  }

  cout << ans;
  return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  if (t == 0) {
    if (s1 != s2) {
      cout << -1;
      return 0;
    }
    cout << s1;
    return 0;
  }

  set<char> f, s, both, fr;
  for (auto &c : s1) f.emplace(c);
  for (auto &c : s2) s.emplace(c);
  for (auto &c : f) {
    if (s.count(c)) both.emplace(c);
  }
  for (char i = 'a'; i <= 'z'; i++) fr.emplace(i);
  for (auto &c : f) fr.erase(c);
  for (auto &c : s) fr.erase(c);

  string ans(n, '0');
  int j = 0;
  V<> mark(n, false);
  for (int i = 0; i < n && j < n - t; i++) {
    if (s1[i] == s2[i]) {
      ans[i] = s1[i];
      j++;
      fr.erase(ans[i]);
      mark[i] = true;
    }
  }
  cerr << j << '\n';
  int now = 0;
  for (int i = 0, p = 0; i < n && j < n - t; i++, p ^= 1) {
    if (s1[i] == s2[i]) continue;
    if (p) {
      ans[i] = s1[i];
    } else {
      ans[i] = s2[i];
    }
    fr.erase(ans[i]);
    j++;
    now++;
    mark[i] = true;
  }
  cerr << now << '\n';
  cerr << ans << '\n';
  if (now & 1) {
    for (int i = 0; i < n; i++) {
      if (mark[i]) {
        if (fr.empty()) {
          cout << -1;
          return 0;
        }
        ans[i] = *fr.begin();
        fr.erase(ans[i]);
        j--;
        break;
      }
    }
  }
  if (j != n - t) {
    cout << -1;
    return 0;
  }

  if (count(all(mark), false) < n - j) {
    cout << -1;
    return 0;
  }

  for (int i = 0; i < n; i++) {
    if (!mark[i]) {
      if (fr.empty()) {
        cout << -1;
        return 0;
      }
      ans[i] = *fr.begin();
      fr.erase(ans[i]);
    }
  }
  int t1 = 0, t2 = 0;
  for (int i = 0; i < n; i++) {
    if (ans[i] != s1[i]) t1++;
    if (ans[i] != s2[i]) t2++;
  }
  if (t1 != t2 || t1 != t) {
    cout << -1;
    return 0;
  }
  cout << ans;
  return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  if (t == 0) {
    if (s1 != s2) {
      cout << -1;
      return 0;
    }
    cout << s1;
    return 0;
  }

  set<char> f, s, both, fr;
  for (auto &c : s1) f.emplace(c);
  for (auto &c : s2) s.emplace(c);
  for (auto &c : f) {
    if (s.count(c)) both.emplace(c);
  }
  for (char i = 'a'; i <= 'z'; i++) fr.emplace(i);
  for (auto &c : f) fr.erase(c);
  for (auto &c : s) fr.erase(c);

  string ans(n, '0');
  int j = 0;
  V<> mark(n, false);
  for (int i = 0; i < n && j < n - t; i++) {
    if (s1[i] == s2[i]) {
      ans[i] = s1[i];
      j++;
      fr.erase(ans[i]);
      mark[i] = true;
    }
  }
  cerr << j << '\n';
  int now = 0;
  for (int i = 0, p = 0; i < n && j < n - t; i++, p ^= 1) {
    if (s1[i] == s2[i]) continue;
    if (p) {
      ans[i] = s1[i];
    } else {
      ans[i] = s2[i];
    }
    fr.erase(ans[i]);
    j++;
    now++;
    mark[i] = true;
  }
  cerr << now << '\n';
  cerr << ans << '\n';
  if (now & 1) {
    for (int i = 0; i < n; i++) {
      if (mark[i]) {
        if (fr.empty()) {
          cout << -1;
          return 0;
        }
        ans[i] = *fr.begin();
        fr.erase(ans[i]);
        j--;
        break;
      }
    }
  }
  if (j != n - t) {
    cout << -1;
    return 0;
  }

  if (count(all(mark), false) < n - j) {
    cout << -1;
    return 0;
  }

  for (int i = 0; i < n; i++) {
    if (!mark[i]) {
      if (fr.empty()) {
        cout << -1;
        return 0;
      }
      ans[i] = *fr.begin();
      fr.erase(ans[i]);
    }
  }

  cout << ans;
  return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  if (t == 0) {
    if (s1 != s2) {
      cout << -1;
      return 0;
    }
    cout << s1;
    return 0;
  }

  set<char> f, s, both, fr;
  for (auto &c : s1) f.emplace(c);
  for (auto &c : s2) s.emplace(c);
  for (auto &c : f) {
    if (s.count(c)) both.emplace(c);
  }
  for (char i = 'a'; i <= 'z'; i++) fr.emplace(i);
  for (auto &c : f) fr.erase(c);
  for (auto &c : s) fr.erase(c);

  string ans(n, '0');
  int j = 0;
  V<> mark(n, false);
  for (int i = 0; i < n && j < n - t; i++) {
    if (s1[i] == s2[i]) {
      ans[i] = s1[i];
      j++;
      fr.erase(ans[i]);
      mark[i] = true;
    }
  }
  cerr << j << '\n';
  int now = 0;
  for (int i = 0, p = 0; i < n && j < n - t; i++, p ^= 1) {
    if (s1[i] == s2[i]) continue;
    if (p) {
      j++;
      ans[i] = s1[i];
    } else {
      ans[i] = s2[i];
    }
    fr.erase(ans[i]);
    now++;
    mark[i] = true;
  }
  cerr << now << '\n';
  cerr << ans << '\n';
  if (now & 1) {
    for (int i = 0; i < n; i++) {
      if (mark[i]) {
        if (fr.empty()) {
          cout << -1;
          return 0;
        }
        ans[i] = *fr.begin();
        fr.erase(ans[i]);
        j--;
        break;
      }
    }
  }

  for (int i = 0; i < n; i++) {
    if (!mark[i]) {
      if (fr.empty()) {
        cout << -1;
        return 0;
      }
      ans[i] = *fr.begin();
      fr.erase(ans[i]);
    }
  }

  int t1 = 0, t2 = 0;
  for (int i = 0; i < n; i++) {
    if (s1[i] != ans[i]) t1++;
    if (s2[i] != ans[i]) t2++;
  }
  cerr << t1 << ' ' << t2 << '\n';
  if (t1 != t2 || t1 != t) {
    cout << -1;
    return 0;
  }
  cout << ans;
  return 0;
}


#include <bits/stdc++.h>

using namespace std;

#ifndef LOCAL
#define cerr if(0) cerr
#endif

#define all(v) (v).begin(), (v).end()
#define X first
#define Y second

using ll = long long;
using ld = long double;

template<class T = int>
using V = vector<T>;
template<class T = int>
using VV = V<V<T>>;
template<class I, class J>
using P = pair<I, J>;
template<class T = int>
using PP = P<T, T>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, t;
  cin >> n >> t;
  string s1, s2;
  cin >> s1 >> s2;

  int eq = 0, neq = 0;
  for (int i = 0; i < n; i++) {
    if (s1[i] != s2[i]) neq++;
    else eq++;
  }

  int eqq = n - t;
  if (neq < 2 * (eqq - eq)) {
    cout << -1;
    return 0;
  }

  set<char> fr;
  for (int c = 'a'; c <= 'z'; c++) {
    fr.emplace(c);
  }

  string ans(n, '0');
  int j = 0;
  for (int i = 0; i < n && j < eqq; i++) {
    if (s1[i] == s2[i]) {
      ans[i] = s1[i];
      j++;
    }
  }

  for (int i = 0; i < n && j < 2 * (eqq - eq); i++) {
    if (s1[i] == s2[i]) continue;
    j++;
    ans[i] = (j & 1 ? s1[i] : s2[i]);
  }

  for (int i = 0; i < n; i++) {
    if (ans[i] == '0') {
      fr.erase(s1[i]);
      fr.erase(s2[i]);
      ans[i] = *fr.begin();
      fr.emplace(s1[i]);
      fr.emplace(s2[i]);

    }
  }

  cout << ans;
  return 0;
}


#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
typedef long long          ll;
typedef unsigned long long ull;
typedef long double        ld;
#define all(A)             A.begin(), A.end()
#define rall(A)            A.rbegin(), A.rend()
#define mem(A, B)          memset(A, B, sizeof A)
#define sorta(A)           sort(all(A))
#define sortd(A)           sort(rall(A))
#define sortf(A, F)        sort(all(A), F)
#define PI                 (acos(0.) * 2)
#define eps                .000000001
#define oo                 1000000000
template <class T> inline void remax(T& A, T B){ if (A < B)A = B; }
template <class T> inline void remin(T& A, T B){ if (A > B)A = B; }
string ToString(ll num){ string ret; bool neg = false; if (num < 0)num *= ~0, neg = true; do{ ret += ((num % 10) + '0'); num /= 10; } while (num); if (neg) ret += '-'; reverse(all(ret)); return ret; }
ll ToNumber(string s){ ll r = 0, p = 1; int e = (s[0] == '-'); for (int i = s.size() - 1; i >= e; --i)r += (s[i] - '0') * p, p *= 10; if (e)r *= ~0; return r; }
ll Gcd(ll a, ll b){ while (a %= b ^= a ^= b ^= a);  return b; }
ll Power(ll base, ull power){ ll ret = 1; while (power){ if (power & 1)ret *= base; power >>= 1; base *= base; } return ret; }
ll PowerMod(ll base, ull power, ll mod){ if (!power)return 1 % mod; if (power & 1)return (base * PowerMod(base, power - 1, mod)) % mod; return PowerMod((base * base) % mod, power >> 1, mod); }
int Log(ll num, ll base){ int ret = 0; while (num){ ++ret; num /= base; } return ret; }

inline void run(){
 char ch1[100001];
 char ch2[100001];
 char ch3[100001];
 int n, t, a = 0;
 scanf("%d%d%s%s", &n, &t, ch1, ch2);
 for (int i = 0; i < n; ++i)
 if (ch1[i] != ch2[i])++a;
 if (t >= a){
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i]){
   char c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  t -= a;
  for (int i = 0; i < n; ++i)
  if (ch1[i] == ch2[i])
  if (!t)ch3[i] = ch1[i];
  else{
   char c = 'a';
   while (c == ch1[i])++c;
   ch3[i] = c;
   --t;
  }
 }
 else{
  int b = a - t;
  if (a + b / 2 != t)return (void)puts("-1");
  int x = 0;
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i])
  if (x == b){
   int c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  else if (x * 2 < b)ch3[i] = ch1[i], ++x;
  else ch3[i] = ch2[i], ++x;
  else ch3[i] = ch1[i];
 }
 for (int i = 0; i < n;)printf("%c", ch3[i++]);
 puts("");
}
int main(){
 FILE *input = stdin;
 FILE *output = stdout;
#ifdef LOCAL
 input = freopen("in.in", "r", stdin);
 output = freopen("out.out", "w", stdout);
#endif
 while (!feof(input)){
  run();
#ifdef LOCAL
  puts("");
#else
  break;
#endif
 }
#ifdef LOCAL
 fprintf(output, "\n\nTime: %d ms\n", (int)(clock() * 1000. / CLOCKS_PER_SEC));
#endif
 return 0;
}


#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
typedef long long          ll;
typedef unsigned long long ull;
typedef long double        ld;
#define all(A)             A.begin(), A.end()
#define rall(A)            A.rbegin(), A.rend()
#define mem(A, B)          memset(A, B, sizeof A)
#define sorta(A)           sort(all(A))
#define sortd(A)           sort(rall(A))
#define sortf(A, F)        sort(all(A), F)
#define PI                 (acos(0.) * 2)
#define eps                .000000001
#define oo                 1000000000
template <class T> inline void remax(T& A, T B){ if (A < B)A = B; }
template <class T> inline void remin(T& A, T B){ if (A > B)A = B; }
string ToString(ll num){ string ret; bool neg = false; if (num < 0)num *= ~0, neg = true; do{ ret += ((num % 10) + '0'); num /= 10; } while (num); if (neg) ret += '-'; reverse(all(ret)); return ret; }
ll ToNumber(string s){ ll r = 0, p = 1; int e = (s[0] == '-'); for (int i = s.size() - 1; i >= e; --i)r += (s[i] - '0') * p, p *= 10; if (e)r *= ~0; return r; }
ll Gcd(ll a, ll b){ while (a %= b ^= a ^= b ^= a);  return b; }
ll Power(ll base, ull power){ ll ret = 1; while (power){ if (power & 1)ret *= base; power >>= 1; base *= base; } return ret; }
ll PowerMod(ll base, ull power, ll mod){ if (!power)return 1 % mod; if (power & 1)return (base * PowerMod(base, power - 1, mod)) % mod; return PowerMod((base * base) % mod, power >> 1, mod); }
int Log(ll num, ll base){ int ret = 0; while (num){ ++ret; num /= base; } return ret; }

inline void run(){
 char ch1[100001];
 char ch2[100001];
 char ch3[100001];
 int n, t, a = 0;
 scanf("%d%d%s%s", &n, &t, ch1, ch2);
 for (int i = 0; i < n; ++i)
 if (ch1[i] != ch2[i])++a;
 if (t >= a){
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i]){
   char c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  t -= a;
  for (int i = 0; i < n; ++i)
  if (ch1[i] == ch2[i])
  if (!t)ch3[i] = ch1[i];
  else{
   char c = 'a';
   while (c == ch1[i])++c;
   ch3[i] = c;
   --t;
  }
 }
 else{
  int b = a - t;
  if (b & 1)return (void)puts("-1");
  if (a + b / 2 != t)return (void)puts("-1");
  int x = 0;
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i])
  if (x == b){
   int c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  else if (x * 2 < b)ch3[i] = ch1[i], ++x;
  else ch3[i] = ch2[i], ++x;
  else ch3[i] = ch1[i];
 }
 for (int i = 0; i < n;)printf("%c", ch3[i++]);
 puts("");
}
int main(){
 FILE *input = stdin;
 FILE *output = stdout;
#ifdef LOCAL
 input = freopen("in.in", "r", stdin);
 output = freopen("out.out", "w", stdout);
#endif
 while (!feof(input)){
  run();
#ifdef LOCAL
  puts("");
#else
  break;
#endif
 }
#ifdef LOCAL
 fprintf(output, "\n\nTime: %d ms\n", (int)(clock() * 1000. / CLOCKS_PER_SEC));
#endif
 return 0;
}


#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
typedef long long          ll;
typedef unsigned long long ull;
typedef long double        ld;
#define all(A)             A.begin(), A.end()
#define rall(A)            A.rbegin(), A.rend()
#define mem(A, B)          memset(A, B, sizeof A)
#define sorta(A)           sort(all(A))
#define sortd(A)           sort(rall(A))
#define sortf(A, F)        sort(all(A), F)
#define PI                 (acos(0.) * 2)
#define eps                .000000001
#define oo                 1000000000
template <class T> inline void remax(T& A, T B){ if (A < B)A = B; }
template <class T> inline void remin(T& A, T B){ if (A > B)A = B; }
string ToString(ll num){ string ret; bool neg = false; if (num < 0)num *= ~0, neg = true; do{ ret += ((num % 10) + '0'); num /= 10; } while (num); if (neg) ret += '-'; reverse(all(ret)); return ret; }
ll ToNumber(string s){ ll r = 0, p = 1; int e = (s[0] == '-'); for (int i = s.size() - 1; i >= e; --i)r += (s[i] - '0') * p, p *= 10; if (e)r *= ~0; return r; }
ll Gcd(ll a, ll b){ while (a %= b ^= a ^= b ^= a);  return b; }
ll Power(ll base, ull power){ ll ret = 1; while (power){ if (power & 1)ret *= base; power >>= 1; base *= base; } return ret; }
ll PowerMod(ll base, ull power, ll mod){ if (!power)return 1 % mod; if (power & 1)return (base * PowerMod(base, power - 1, mod)) % mod; return PowerMod((base * base) % mod, power >> 1, mod); }
int Log(ll num, ll base){ int ret = 0; while (num){ ++ret; num /= base; } return ret; }

inline void run(){
 char ch1[100001];
 char ch2[100001];
 char ch3[100001];
 int n, t, a = 0, b = 0;
 scanf("%d%d%s%s", &n, &t, ch1, ch2);
 for (int i = 0; i < n; ++i)
 if (ch1[i] != ch2[i])++a;
 else++b;
 if (t >= a){
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i]){
   char c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  t -= a;
  for (int i = 0; i < n; ++i)
  if (ch1[i] == ch2[i])
  if (!t)ch3[i] = ch1[i];
  else{
   char c = 'a';
   while (c == ch1[i])++c;
   ch3[i] = c;
   --t;
  }
 }
 else{
  int p = 0;
  int aa = 0;
  while (a + aa != t){
   int z = 0;
   for (int i = p; i < n; ++i)
   if (ch1[i] != ch2[i]){
    if (++z == 2)break;
   }
   if (z != 2)break;
   for (int i = p; i < n; ++i)
   if (ch1[i] != ch2[i])
   if (z == 2)ch3[i] = ch1[i], --z;
   else{
    ch3[i] = ch2[i];
    p = i + 1;
    break;
   }
   --a;
   ++aa;
  }
  if (a + aa != t)return (void)puts("-1");
  for (int i = p; i < n; ++i)
  if (ch1[i] != ch2[i]){
   char c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  for (int i = 0; i < n; ++i)
  if (ch1[i] == ch2[i])ch3[i] = ch1[i];
 }
 for (int i = 0; i < n;)printf("%c", ch3[i++]);
 puts("");
}
int main(){
 FILE *input = stdin;
 FILE *output = stdout;
#ifdef LOCAL
 input = freopen("in.in", "r", stdin);
 output = freopen("out.out", "w", stdout);
#endif
 while (!feof(input)){
  run();
#ifdef LOCAL
  puts("");
#else
  break;
#endif
 }
#ifdef LOCAL
 fprintf(output, "\n\nTime: %d ms\n", (int)(clock() * 1000. / CLOCKS_PER_SEC));
#endif
 return 0;
}


#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
typedef long long          ll;
typedef unsigned long long ull;
typedef long double        ld;
#define all(A)             A.begin(), A.end()
#define rall(A)            A.rbegin(), A.rend()
#define mem(A, B)          memset(A, B, sizeof A)
#define sorta(A)           sort(all(A))
#define sortd(A)           sort(rall(A))
#define sortf(A, F)        sort(all(A), F)
#define PI                 (acos(0.) * 2)
#define eps                .000000001
#define oo                 1000000000
template <class T> inline void remax(T& A, T B){ if (A < B)A = B; }
template <class T> inline void remin(T& A, T B){ if (A > B)A = B; }
string ToString(ll num){ string ret; bool neg = false; if (num < 0)num *= ~0, neg = true; do{ ret += ((num % 10) + '0'); num /= 10; } while (num); if (neg) ret += '-'; reverse(all(ret)); return ret; }
ll ToNumber(string s){ ll r = 0, p = 1; int e = (s[0] == '-'); for (int i = s.size() - 1; i >= e; --i)r += (s[i] - '0') * p, p *= 10; if (e)r *= ~0; return r; }
ll Gcd(ll a, ll b){ while (a %= b ^= a ^= b ^= a);  return b; }
ll Power(ll base, ull power){ ll ret = 1; while (power){ if (power & 1)ret *= base; power >>= 1; base *= base; } return ret; }
ll PowerMod(ll base, ull power, ll mod){ if (!power)return 1 % mod; if (power & 1)return (base * PowerMod(base, power - 1, mod)) % mod; return PowerMod((base * base) % mod, power >> 1, mod); }
int Log(ll num, ll base){ int ret = 0; while (num){ ++ret; num /= base; } return ret; }

inline void run(){
 char ch1[100001];
 char ch2[100001];
 char ch3[100001];
 int n, t, a = 0;
 scanf("%d%d%s%s", &n, &t, ch1, ch2);
 for (int i = 0; i < n; ++i)
 if (ch1[i] != ch2[i])++a;
 if (t >= a){
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i]){
   char c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  t -= a;
  for (int i = 0; i < n; ++i)
  if (ch1[i] == ch2[i])
  if (!t)ch3[i] = ch1[i];
  else{
   char c = 'a';
   while (c == ch1[i])++c;
   ch3[i] = c;
   --t;
  }
 }
 else{
  int b = a - t;
  if (b & 1)return (void)puts("-1");
  int x = 0;
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i])
  if (x == b){
   int c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  else if (x * 2 < b)ch3[i] = ch1[i], ++x;
  else ch3[i] = ch2[i], ++x;
  else ch3[i] = ch1[i];
 }
 for (int i = 0; i < n;)printf("%c", ch3[i++]);
 puts("");
}
int main(){
 FILE *input = stdin;
 FILE *output = stdout;
#ifdef LOCAL
 input = freopen("in.in", "r", stdin);
 output = freopen("out.out", "w", stdout);
#endif
 while (!feof(input)){
  run();
#ifdef LOCAL
  puts("");
#else
  break;
#endif
 }
#ifdef LOCAL
 fprintf(output, "\n\nTime: %d ms\n", (int)(clock() * 1000. / CLOCKS_PER_SEC));
#endif
 return 0;
}


#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
typedef long long          ll;
typedef unsigned long long ull;
typedef long double        ld;
#define all(A)             A.begin(), A.end()
#define rall(A)            A.rbegin(), A.rend()
#define mem(A, B)          memset(A, B, sizeof A)
#define sorta(A)           sort(all(A))
#define sortd(A)           sort(rall(A))
#define sortf(A, F)        sort(all(A), F)
#define PI                 (acos(0.) * 2)
#define eps                .000000001
#define oo                 1000000000
template <class T> inline void remax(T& A, T B){ if (A < B)A = B; }
template <class T> inline void remin(T& A, T B){ if (A > B)A = B; }
string ToString(ll num){ string ret; bool neg = false; if (num < 0)num *= ~0, neg = true; do{ ret += ((num % 10) + '0'); num /= 10; } while (num); if (neg) ret += '-'; reverse(all(ret)); return ret; }
ll ToNumber(string s){ ll r = 0, p = 1; int e = (s[0] == '-'); for (int i = s.size() - 1; i >= e; --i)r += (s[i] - '0') * p, p *= 10; if (e)r *= ~0; return r; }
ll Gcd(ll a, ll b){ while (a %= b ^= a ^= b ^= a);  return b; }
ll Power(ll base, ull power){ ll ret = 1; while (power){ if (power & 1)ret *= base; power >>= 1; base *= base; } return ret; }
ll PowerMod(ll base, ull power, ll mod){ if (!power)return 1 % mod; if (power & 1)return (base * PowerMod(base, power - 1, mod)) % mod; return PowerMod((base * base) % mod, power >> 1, mod); }
int Log(ll num, ll base){ int ret = 0; while (num){ ++ret; num /= base; } return ret; }

inline void run(){
 char ch1[100001];
 char ch2[100001];
 char ch3[100001];
 int n, t, a = 0, b = 0;
 scanf("%d%d%s%s", &n, &t, ch1, ch2);
 for (int i = 0; i < n; ++i)
 if (ch1[i] != ch2[i])++a;
 else++b;
 if (t >= a){
  for (int i = 0; i < n; ++i)
  if (ch1[i] != ch2[i]){
   char c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  t -= a;
  for (int i = 0; i < n; ++i)
  if (ch1[i] == ch2[i])
  if (!t)ch3[i] = ch1[i];
  else{
   char c = 'a';
   while (c == ch1[i])++c;
   ch3[i] = c;
   --t;
  }
 }
 else{
  int p = 0;
  while (a != t){
   int z = 0;
   for (int i = p; i < n; ++i)
   if (ch1[i] != ch2[i]){
    if (++z == 2)break;
   }
   if (z != 2)break;
   for (int i = p; i < n; ++i)
   if (ch1[i] != ch2[i])
   if (z == 2)ch3[i] = ch1[i], --z;
   else{
    ch3[i] = ch2[i];
    p = i + 1;
    break;
   }
   --a;
  }
  if (a != t)return (void)puts("-1");
  for (int i = p; i < n; ++i)
  if (ch1[i] != ch2[i]){
   char c = 'a';
   while (c == ch1[i] || c == ch2[i])++c;
   ch3[i] = c;
  }
  for (int i = 0; i < n; ++i)
  if (ch1[i] == ch2[i])ch3[i] = ch1[i];
 }
 for (int i = 0; i < n;)printf("%c", ch3[i++]);
 puts("");
}
int main(){
 FILE *input = stdin;
 FILE *output = stdout;
#ifdef LOCAL
 input = freopen("in.in", "r", stdin);
 output = freopen("out.out", "w", stdout);
#endif
 while (!feof(input)){
  run();
#ifdef LOCAL
  puts("");
#else
  break;
#endif
 }
#ifdef LOCAL
 fprintf(output, "\n\nTime: %d ms\n", (int)(clock() * 1000. / CLOCKS_PER_SEC));
#endif
 return 0;
}


#include<cassert>

#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    k=23205;
    m=21319;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=k&1;
        m-=t;
        int p=k>>1;
        int q=p>>1;

        if( m>n-m )
        {
            p-=m+m-n;
            q-=m+m-n;
            t+=m+m-n;
            m-=m+m-n;
        }

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( t-->0 )
                    c[i]=get(a[i], b[i]);
                else if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
            }
        }

        printf("%s\n", c);
    }
}


#include<cassert>

#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=(k&1) ? ((m-1)>>1<<1)|1 : m>>1<<1 ;
        t=min(t, (k>>1<<1)|(k&1));
        int p=(k-t)>>1;
        int q=(k-t)>>1;
        m-=t+p;

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( t-->0 )
                    c[i]=get(a[i], b[i]);
                else if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
            }
        }

        assert(m<=0 && t<=0 && p<=0 && q<=0);
        printf("%s\n", c);
    }
}


#include<cassert>

#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=(k&1) ? ((m-1)>>1<<1)|1 : m>>1<<1 ;
        t=min(t, (k>>1<<1)|(k&1));
        int p=(k-t)>>1;
        int q=(k-t)>>1;
        int mm=m;
        m-=t+p;

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( t-->0 )
                    c[i]=get(a[i], b[i]);
                else if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
            }
        }

        p=q=0;

        for(int i=0; i<n; i++)
        {
            if( a[i]!=c[i] )
                p++;

            if( b[i]!=c[i] )
                q++;
        }

        if( p!=mm || q!=mm )
            printf("%d %d\n", p, q);

        printf("%s\n", c);
    }
}


#include<cassert>

#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=k&1;
        int p=k>>1;
        int q=k>>1;
        m-=t+p;

        if( m>n-k )
        {
            p-=m-n+k;
            q-=m-n+k;
            t+=m-n+k;
            m-=m-n+k;
        }

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( t-->0 )
                    c[i]=get(a[i], b[i]);
                else if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
            }
        }

        printf("%s\n", c);
    }
}


#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=k&1;
        t+=min((m-t)^((m-t)&1), k^t);
        int p=(k-t)>>1;
        int q=(k-t)>>1;
        m-=t+p;

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m>0 )
                {
                    c[i]=get(a[i], b[i]);
                    m--;
                }
                else
                    c[i]=a[i];
            }
            else
            {
                if( t>0 )
                {
                    c[i]=get(a[i], b[i]);
                    t--;
                }
                else if( p>0 )
                {
                    c[i]=a[i];
                    p--;
                }
                else if( q>0 )
                {
                    c[i]=b[i];
                    q--;
                }
            }
        }

        printf("%s\n", c);
    }
}


#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=(k&1) ? ((m-1)>>1<<1)|1 : m>>1<<1 ;
        int p=(k-t)>>1;
        int q=(k-t)>>1;
        m-=t+p;

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( t-->0 )
                    c[i]=get(a[i], b[i]);
                else if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
            }
        }

        printf("%s\n", c);
    }
}


#include<cassert>

#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=(k&1) ? ((m-1)>>1<<1)|1 : m>>1<<1 ;
        t=min(t, (k>>1<<1)|(k&1));
        int p=(k-t)>>1;
        int q=(k-t)>>1;
        int mm=m;
        m-=t+p;

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( t-->0 )
                    c[i]=get(a[i], b[i]);
                else if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
            }
        }

        p=q=0;

        for(int i=0; i<n; i++)
        {
            if( a[i]!=c[i] )
                p++;

            if( b[i]!=c[i] )
                q++;
        }

        if( p!=mm || q!=mm )
            printf("%d %d %d\n", k, p, q);

        printf("%s\n", c);
    }
}


#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int t=(k&1) ? ((m-1)>>1<<1)|1 : m>>1<<1 ;
        t=min(t, (k>>1<<1)|(k&1));
        int p=(k-t)>>1;
        int q=(k-t)>>1;
        m-=t+p;

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( t-->0 )
                    c[i]=get(a[i], b[i]);
                else if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
            }
        }

        printf("%s\n", c);
    }
}


#include<cassert>

#include<cstdio>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int N=1<<20;
char a[N]={0}, b[N]={0}, c[N]={0};

char get(char x, char y)
{
    char z;

    do{
        z=rand()%26+'a';
    }while( z==x || z==y );

    return z;
}

int main()
{
    int n, m, k=0;
    scanf("%d%d%s%s", &n, &m, a, b);

    for(int i=0; i<n; i++)
        if( a[i]!=b[i] )
            k++;

    if( (k+1)>>1>m )
        printf("-1\n");
    else
    {
        int p=k>>1;
        int q=k>>1;
        m-=(k&1)+p;

        if( m>n-k )
        {
            p-=m-n+k;
            q-=m-n+k;
            m-=m-n+k;
        }

        for(int i=0; i<n; i++)
        {
            if( a[i]==b[i] )
            {
                if( m-->0 )
                    c[i]=get(a[i], b[i]);
                else
                    c[i]=a[i];
            }
            else
            {
                if( p-->0 )
                    c[i]=a[i];
                else if( q-->0 )
                    c[i]=b[i];
                else
                    c[i]=get(a[i], b[i]);
            }
        }

        printf("%s\n", c);
    }
}


import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int n,min=1000000000,ans=0;
        Scanner input= new Scanner(System.in);
        n= input.nextInt();
        int a[]= new int[n];
        int aa[]= new int[n];

        for(int i=0;i<n;i++){
            a[i]=input.nextInt();
            if(min>a[i])
                {min=a[i]; ans=i+1;}
        }

        Arrays.sort(a);

        for(int i=0;i<n-1;i++){
            for(int j=i+1;j<n;j++)
            if(a[i]==a[j])
                {System.out.print("Still Rozdil");
                System.exit(0);
                }
         }

        System.out.print(ans);

    }

}


import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int n,min=1000000000,ans=0;
        Scanner input= new Scanner(System.in);
        n= input.nextInt();
        int a[]= new int[n];
        int aa[]= new int[n];

        for(int i=0;i<n;i++){
            a[i]=input.nextInt();
            if(min>a[i])
                {min=a[i];
                ans=i+1;
                }
        }
        Arrays.sort(a);

        for(int i=0;i<n-1;i++){
            if(a[i]==a[i+1])
                {System.out.print("Still Rozdil");
                System.exit(0);
                }
         }

        System.out.print(ans);

    }

}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class LittleElephantAndRozdil {

	public static void main(String[] args) throws IOException {
		PrintWriter out = new PrintWriter(System.out);
		sc = new StringTokenizer(br.readLine());
		int n = nxtInt();
		int min = 1000000001;
		int minc = 0;
		int mini = 0;
		for (int i = 1; i <= n; i++) {
			int x = nxtInt();
			if (x < min) {
				min = x;
				minc = 1;
				mini = i;
			} else if (x == min)
				minc++;
		}
		if (minc == 1)
			out.println(mini);
		else
			out.println("Still Rozdil");
		br.close();
		out.close();
	}

	static BufferedReader br = new BufferedReader(new InputStreamReader(
			System.in));

	static StringTokenizer sc;

	static String nxtTok() throws IOException {
		while (!sc.hasMoreTokens()) {
			String s = br.readLine();
			if (s == null)
				return null;
			sc = new StringTokenizer(s.trim());
		}
		return sc.nextToken();
	}

	static int nxtInt() throws IOException {
		return Integer.parseInt(nxtTok());
	}

	static long nxtLng() throws IOException {
		return Long.parseLong(nxtTok());
	}
}


import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class LittleElephantAndRodzil_205A {

    public static class Pair implements Comparable<Pair>{

        int x, y;

        public Pair(int x, int y) {
            this.x = x;
            this.y = y;
        }

        @Override
        public int compareTo(Pair o) {
            if( this.y != o.y )
                return this.y-o.y;
            return this.x-o.x;
        }

    }

    public static void main(String[] args)throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        StringTokenizer st = new StringTokenizer(br.readLine());
        Pair v[] = new Pair[n];
        for(int i=0; i<n; i++){
            v[i] = new Pair(i+1, Integer.parseInt(st.nextToken()));
        }
        Arrays.sort(v);
        if(n>1 && v[1].y == v[0].y)
            System.out.println("Still Rozdil");
        else
            System.out.println(v[0].x);
    }
}


import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int x = input.nextInt();
        ArrayList<Integer> al = new ArrayList<Integer>();
        for(int i =0 ; i < x;i++){
            al.add(input.nextInt());
        }
        int min = Collections.min(al);
        int freq = Collections.frequency(al, min);
        if(freq == 1){
            System.out.println(al.indexOf(min)+1);
        }else{
            System.out.println("Still Rozdil");
        }
    }
}


import java.util.Scanner;

/**
 *
 * @author kai
 */
public class JavaApplication2 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] a1 = new int[n];
        int min =2000000000;
        int counter=0;
        int order=0;
        for (int i = 0; i < n; i++) {
            a1[i]=in.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if(min > a1[i]){
            min=a1[i];
            counter=0;
            order=i+1;
            }else if (min==a1[i]){
            counter++;

            }
        }
        if(counter>0){
            System.out.println("Still Rozdil");
        }else{
            System.out.println(order);
        }

    }
}


import java.util.Scanner;

/**
 *
 * @author mayukh
 */
public class Code {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner s=new Scanner(System.in);
       int n=s.nextInt();
   int x[]=new int[n];
        for(int i=0;i<n;i++){
        x[i]=s.nextInt();
        }
      int c=0,k=0,min=x[0];
        for(int j=0;j<n;j++)
        {
            if(x[j]<min){
                min=x[j];
                   k=j;  }

        }
        for(int i=0;i<n;i++)
        {
            if(x[i]==min)
                c++;
            if(c==2){
            System.out.println("Still Rozdil");
            System.exit(0);
            }
        }
        System.out.println(k+1);

    }
}


import java.util.Scanner;

/**
 *
 * @author mayukh
 */
public class Code {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner s=new Scanner(System.in);
        int n=s.nextInt();
        int x[]=new int[n];
        for(int i=0;i<n;i++){
        x[i]=s.nextInt();
        }
      int c=0,k=0,min=x[0];
        for(int j=0;j<n;j++)
        {
            if(x[j]<min)
                min=x[j];
                   k=j;

        }
        for(int i=0;i<n;i++)
        {
            if(x[i]==min)
                c++;
            if(c==2){
            System.out.println("Still Rozdil");
            System.exit(0);
            }
        }
        System.out.println(k+1);

    }
}


import java.util.Scanner;

/**
 *
 * @author mayukh
 */
public class Code {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner s=new Scanner(System.in);
        int n=s.nextInt();
        int x[]=new int[n];
        for(int i=0;i<n;i++){
        x[i]=s.nextInt();
        }
      int min=x[0],c=0;
        for(int j=0;j<n;j++)
        {
            if(x[j]<min)
                min=x[j];
        }
        for(int i=0;i<n;i++)
        {
            if(x[i]==min)
                c++;
            if(c==2){
            System.out.println("Still Rozdil");
            System.exit(0);
            }
        }
        System.out.println(min);

    }
}


import java.util.Scanner;

public class Code {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner s=new Scanner(System.in);
        int n=s.nextInt();
        int x[]=new int[n];
        for(int i=0;i<n;i++){
        x[i]=s.nextInt();
        }
      int min=x[0],c=0;
        for(int j=0;j<n;j++)
        {
            if(x[j]<min)
                min=x[j];
        }
        for(int i=0;i<n;i++)
        {
            if(x[i]==min)
                c++;
            if(c==2){
            System.out.println("Still Rozdil");
            System.exit(0);
            }
        }
        System.out.println(min);

    }
}


import java.util.Arrays;
import java.util.Scanner;

/**
 *
 * @author takhi
 */
public class rozdill_205A {
 public static void main(String args[]){
     Scanner sc=new Scanner(System.in);
     int n=sc.nextInt();
     int min=100000;
     int[] arr=new int[n];
     int a[]=new int[n];
     for(int i=0;i<n;i++){
         arr[i]=sc.nextInt();
     }
     for(int i=0;i<n;i++){
         a[i]=arr[i];
     }

     Arrays.sort(arr);
     int j=0;
     if(n>1){
     for(int i=0;i<n-1;i++){
         if(arr[i]==arr[i+1]){
             System.out.println("Still Rozdil");
             outer:break;
         }

             else {while(a[j]!=arr[0]){
                 j++;

             }
              System.out.println(j+1);
              outer:break;
         }

     }
     }else System.out.println("1");
 }
}


import java.util.Arrays;
import java.util.Scanner;

/**
 *
 * @author takhi
 */
public class rozdill_205A {
 public static void main(String args[]){
     Scanner sc=new Scanner(System.in);
     int n=sc.nextInt();

     int[] arr=new int[n];
     int a[]=new int[n];
     for(int i=0;i<n;i++){
         arr[i]=sc.nextInt();
     }
     for(int i=0;i<n;i++){
         a[i]=arr[i];
     }

     Arrays.sort(arr);
     int j=0;
     for(int i=1;i<n;i++){
         if(arr[i-1]==arr[i]){
             System.out.println("Still Rozdil");
             outer:break;
         }

             else {while(a[j]!=arr[0]){
                 j++;

             }
              System.out.println(j+1);
              outer:break;
         }

     }
 }
}


import java.util.Arrays;
import java.util.Scanner;

public class A_205_Little_Elephant_and_Rozdil {
	static class sort implements Comparable<sort> {
		int x;
		int i;

		public sort(int x, int i) {
			this.x = x;
			this.i = i;
		}

		public int compareTo(sort arg0) {
			if (this.x > arg0.x)
				return 1;
			return 0;
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		sort a[] = new sort[n + 1];
		for (int i = 1; i <= n; i++) {
			int x = sc.nextInt();
			a[i] = new sort(x, i);
		}
		Arrays.sort(a, 1, n + 1);
		if (n == 1) {
			System.out.println(1);
			return;
		}
		if (a[1].x != a[2].x)
			System.out.println(a[1].i);
		else
			System.out.println("Still Rozdil");
	}
}


import java.util.Arrays;
import java.util.Scanner;

public class A_205_Little_Elephant_and_Rozdil {
	static class sort implements Comparable<sort> {
		int x;
		int i;

		public sort(int x, int i) {
			this.x = x;
			this.i = i;
		}

		public int compareTo(sort arg0) {
			if (this.x > arg0.x)
				return 1;
			else if(this.x<arg0.x)
				return -1;
			return 0;
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		sort a[] = new sort[n + 1];
		for (int i = 1; i <= n; i++) {
			int x = sc.nextInt();
			a[i] = new sort(x, i);
		}
		Arrays.sort(a, 1, n + 1);
		if (n == 1) {
			System.out.println(1);
			return;
		}
		if (a[1].x != a[2].x)
			System.out.println(a[1].i);
		else
			System.out.println("Still Rozdil");
	}
}


import java.util.Arrays;
import java.util.Scanner;

public class LilElephants {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n;
        n = sc.nextInt();
        int[] i = new int[n];
        int[] l = new int[n];
        for (int j = 0; j < n; j++) {
            i[j] = sc.nextInt();
            l[j] = i[j];
        }
        if (n == 1) {
            System.out.println("1");
        }
        if (n != 1) {
            Arrays.sort(l);
            if (l[0] == l[1]) {
                System.out.println("Still Rozdil");
            } else {
                for (int j = 0; j < n; j++) {
                    if (l[0] == i[j]) {
                        System.out.println(j + 1);
                    }
                }
            }

        }
    }
}


import java.util.Arrays;
import java.util.Scanner;

public class LilElephants {

    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n;
        n=sc.nextInt();
        int []i=new int[n];
        int []l=new int[n];
        for(int j=0;j<n;j++)
        {
            i[j]=sc.nextInt();
            l[j]=i[j];
        }
        Arrays.sort(l);
        if(l[0]==l[1])
        {
            System.out.println("Still Rozdil");
        }
        else
            for(int j=0;j<n;j++)
            {
                if(l[0]==i[j])
                {
                    System.out.println(j+1);
                }
            }

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int a[] = new int [2147483647];
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();

        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 2147483647;

        for(int j=0;j<i;j++){
            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag==true) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int a[] = new int [9999];
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();

        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 2147483647;

        for(int j=0;j<i;j++){
            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag==true) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int a[] = new int [999];
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();

        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 2147483647;

        for(int j=0;j<i;j++){
            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag==true) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();
        int a[] = new int [i];
        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 2147483647;

        for(int j=0;j<i;j++){

            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int a[] = new int [999];
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();

        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 999999999;

        for(int j=0;j<i;j++){
            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag==true) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int a[] = new int [5000];
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();

        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 2147483647;

        for(int j=0;j<i;j++){
            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag==true) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int a[] = new int [214748364];
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();

        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 2147483647;

        for(int j=0;j<i;j++){
            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag==true) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;

public class test {
    public static void main(String args[]){
        int i = 0;
        int a[] = new int [7000];
        int small = 0;
        int answer = 0;
        boolean flag = false;

        Scanner input = new Scanner(System.in);
        i=input.nextInt();

        for(int j=0;j<i;j++){
            a[j] = input.nextInt();
        }

        small = 2147483647;

        for(int j=0;j<i;j++){

            if(a[j] < small){
                small = a[j];
                answer = j+1;
                if(flag = true) flag=false;
            }

            else if(small == a[j]){
                flag = true;
            }

        }

        if(flag==true) System.out.println("Still Rozdil");
        else System.out.print(answer);

    }
}


import java.util.Scanner;
import java.util.ArrayList;
import java.util.Collections;
public class a {
  public static void main(String[] args) {
    Scanner in=new Scanner(System.in);
    ArrayList<Integer> list=new ArrayList<Integer>();
    int n=in.nextInt();
    for(int i=0;i<n;i++)
      list.add((Integer)in.nextInt());
    int min=list.get(0);
    for(int i=1;i<list.size();i++)
      if(list.get(i)<min)
      min=list.get(i);
    System.out.println(Collections.frequency(list,min)>1?"Still Rozdil":list.indexOf(min)+1);
  }
}


import java.util.*;
import java.io.*;

public class Main {
public static void main(String[] args) throws IOException{
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
long min = 1000000001;
int mini = -1;
boolean b = false;
for (int i=0; i<n; i++) {
  long x = sc.nextLong();
  if (x<min){
    min=x;
    b=false;
    mini = i+1;
  } else if (x==min){b=true;}
}

System.out.println(b?"Still Rozdil":mini);

}
}


import java.util.Scanner;

public class A205 {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int N = input.nextInt();
        int minTime = Integer.MAX_VALUE;
        int city = 0;
        for (int n=1; n<=N; n++) {
            int time = input.nextInt();
            if (time == minTime) {
                city = 0;
            } else if (time < minTime) {
                minTime = time;
                city = n;
            }
        }
        if (city == 0) {
            System.out.println("Still Rozdil");
        } else {
            System.out.println(city);
        }
    }

}


import java.util.*;
import static java.lang.Math.*;
public class ProblemA {
    void run() {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int min = Integer.MAX_VALUE;
        int mini = -1;
        for (int i = 0; i < n; i++) {
        	int dist = sc.nextInt();
        	if (dist < min) {
        		min = dist;
        		mini = i+1;
        	} else if (dist == min) {
        		p("Still Rozdil\n");
        		return;
        	}
        }

        p("%d\n", mini);
    }

    boolean debug = false;
    void p(String f, Object...params) {
        System.out.printf(f, params);
    }
    void d(Object...params) {
        if (debug) {
            p("DEBUG: %s\n", Arrays.deepToString(params));
        }
    }
    public ProblemA(String[] args) {
        if (args.length > 0 && args[0].equals("debug")) {
            debug = true;
        }
    }
    public static void main(String[] args) {
        new ProblemA(args).run();
    }
}


import java.util.*;
import static java.lang.Math.*;
public class ProblemA {
    void run() {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        boolean unique = true;
        int min = Integer.MAX_VALUE;
        int mini = -1;
        for (int i = 0; i < n; i++) {
        	int dist = sc.nextInt();
        	if (dist < min) {
        		unique = true;
        		min = dist;
        		mini = i+1;
        	} else if (dist == min) {
        		unique = false;
        	}
        }
        if (unique) {
            p("%d\n", mini);
        } else {
    		p("Still Rozdil\n");
        }

    }

    boolean debug = false;
    void p(String f, Object...params) {
        System.out.printf(f, params);
    }
    void d(Object...params) {
        if (debug) {
            p("DEBUG: %s\n", Arrays.deepToString(params));
        }
    }
    public ProblemA(String[] args) {
        if (args.length > 0 && args[0].equals("debug")) {
            debug = true;
        }
    }
    public static void main(String[] args) {
        new ProblemA(args).run();
    }
}


import java.util.Scanner;

public class Little_Elepha {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in) ;  ;
        long n = in.nextLong() ;
        long min ;
        int index=1 ;
        boolean test = false  ;
        long t = in.nextLong() ;
        min = t ;
        for(int i=1; i<=n-1 ; i++)
        {
            t = in.nextLong() ;
            if(t<min){
                min = t ;
                index = i+1 ;
                test=false ;
            }
            else if(t==min)test=true ;
        }
        if(test==false)System.out.println(index);
        else System.out.println("Still Rozdil");

    }

}


import java.util.Scanner;

public class Little_Elepha {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in) ;  ;
        long n = in.nextLong() ;
        long min =999999999;
        int index=0 ;
        boolean test = false  ;
        for(int i=0; i<n ; i++)
        {
            long t = in.nextLong() ;
            if(t<min){
                min = t ;
                index = i+1 ;
                test=false ;
            }
            else if(t==min)test=true ;
        }
        if(test==false)System.out.println(index);
        else System.out.println("Still Rozdil");

    }

}


import java.util.Scanner;

public class Little_Elepha {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in) ;  ;
        long n = in.nextLong() ;
        long min =99999999;
        int index=0 ;
        boolean test = false  ;
        for(int i=0; i<n ; i++)
        {
            long t = in.nextLong() ;
            if(t<min){
                min = t ;
                index = i+1 ;
                test=false ;
            }
            else if(t==min)test=true ;
        }
        if(test==false)System.out.println(index);
        else System.out.println("Still Rozdil");

    }

}


import java.util.*;
public class Main {

    public static void main (String[] args){
        Scanner in = new Scanner (System.in);
        int n = in.nextInt();
        ArrayList <Integer> l = new ArrayList<>();
        for (int i=0 ; i<n ; i++)
            l.add(in.nextInt());
        int min = l.get(0);
        for (int i=1 ; i<n ; i++){
            if (l.get(i) < min)
                min = l.get(i);
        }
        int flag = 0;
        for (int i=0 ; i<n ; i++){
            if (l.get(i) == min)
                    ++flag;
        }
        if (flag == 1)
            System.out.println(l.indexOf(min)+1);
        else
            System.out.println("Still Rozdil");

    }
}


import java.util.*;
public class Main {

    public static void main (String[] args){
        Scanner in = new Scanner (System.in);
        int n = in.nextInt();
        ArrayList <Integer> l = new ArrayList<>();
        for (int i=0 ; i<n ; i++)
            l.add(in.nextInt());
        int min = l.get(0);
        for (int i=1 ; i<n ; i++){
            if (l.get(i) < min)
                min = l.get(i);
        }
        int flag = 0;
        for (int i=1 ; i<n ; i++){
            if (l.get(i) == min)
                    flag++;
        }
        if (flag == 1)
            System.out.println(l.indexOf(min)+1);
        else
            System.out.println("Still Rozdil");

    }
}


import java.util.Scanner;

public class LittleElephantandRozdil {
    public static void main(String[]args){
        Scanner in=new Scanner(System.in);
    int n=in.nextInt(),i=0;
int min=1000000000;
boolean flag=true;
int a,b=0;
    while(n-->0){
        i++;
        if(min>( a=in.nextInt())){
            min=a;
            b=i;

        }else if(min==a){
            flag=false;
        }
    }

    if(!flag){
        System.out.println("Still Rozdil");
    }else
        System.out.println(b);

    }
}


import java.util.Scanner;

public class LittleElephantandRozdil {
	public static void main(String[]args){
		Scanner in=new Scanner(System.in);
	int n=in.nextInt(),i=0;
int min=Integer.MAX_VALUE;
boolean flag=true;
int a,b=0;
	while(n-->0){
		i++;
		if(min>( a=in.nextInt())){
			min=a;
			b=i;
			flag=true;
		}else if(min==a){
			flag=false;
		}
	}

	if(!flag){
		System.out.println("Still Rozdil");
	}else
		System.out.println(b);

	}
}


import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Scanner;

public class LittleElephantandRozdil {
    public static void main(String[]args){
        Scanner in=new Scanner(System.in);
    int n=in.nextInt(),i=0;
int min=1000000000;
boolean flag=true;
int a,b=0;
    while(n-->0){
        i++;
        if(min>( a=in.nextInt())){
            min=a;
            b=i;
            flag=true;
        }else if(min==a){
            flag=false;
        }
    }

    if(!flag){
        System.out.println("Still Rozdil");
    }else
        System.out.println(b);

    }
}


import java.util.*;
public class LittleElephantAndRozdil {
    public static void main(String[] Args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int min = 1000000001;
        int cur = 0;
        int ind = -1;
        for(int k =0;k<n;k++){
            int a = sc.nextInt();
            if(min==a)
                cur++;
            if(min>a){
                min = a;
                cur = 1;
                ind = k+1;
            }
        }
        if(cur==1)
            System.out.println(ind);
        else
            System.out.println("Still Rozdil");
    }
}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		String y[] = in.readLine().split(" ");
		int n = Integer.parseInt(y[0]);
		y = in.readLine().split(" ");

		int lastmin = Integer.parseInt(y[0]);
		int min = lastmin;
		int index=1;
		boolean flag = true;

		int temp;
		for (int i = 1; i < n; i++) {
			temp=Integer.parseInt(y[i]);
			if ( temp< min ) {
				lastmin=temp;
				min=temp;
				index=i+1;
				if(!flag)
					flag=true;
			}else if(temp== min){
				flag=false;
			}

		}
		if (flag)
			System.out.println(index);
		else
			System.out.println("Still Rozdil");

	}
}


import java.util.*;
import java.lang.*;
public class A205
	{
	public static void main(String[] args)
		{
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		int i=0;
		Data a[] = new Data[n];
		for(i=0;i<n;i++)
			{
			a[i]=new Data(in.nextInt(),i+1);
			}
		a=MergeSort(a,0,n-1);
		if(a[0].getValue()!=a[1].getValue())
			{
			System.out.println(a[0].getIndex());
			}
		else
			{
			System.out.println("Still Rozdil");
			}
		}
	public static Data[] MergeSort(Data[] a,int low,int high)
		{
		if(low>=high)
			{
			return a;
			}
		else
			{
			int middle=(high+low)/2;
			Data[] left = new Data [middle-low+1];
			Data[] right = new Data [high-middle];
			int i=0,count=0;
			for(i=0;i<=middle-low;i++)
				{
				left[count]=a[i];count++;
				}
			count=0;
			for(i=middle+1-low;i<=high-low;i++)
				{
				right[count]=a[i];count++;
				}
			Data[] SortedLeft =MergeSort(left,low,middle);
			Data[] SortedRight =MergeSort(right,middle+1,high);
			return Merge(SortedLeft,SortedRight,low,high);
			}
		}
	public static Data[] Merge(Data[] sl,Data[] sr,int low,int high)
		{
		Data fina[]  = new Data[high-low+1];
		int i=0,middle =(high+low)/2;
		int a=0,b=0,alimit=middle-low+1,blimit=high-middle;
		int n=alimit+blimit;
		/*System.out.println("sl");
		for(i=0;i<alimit;i++)
			{
			int x = sl[i].getValue();
			int y = sl[i].getIndex();
			System.out.println(x+" "+y);
			}
		System.out.println("sr");
		for(i=0;i<blimit;i++)
			{
			int x = sr[i].getValue();
			int y = sr[i].getIndex();
			System.out.println(x+" "+y);
			}*/
		for(i=0;i<n;i++)
			{
			if(a!=alimit&&(b==blimit||(sl[a].getValue()<=sr[b].getValue()&&a<alimit)))
				{
				fina[i]=new Data(sl[a].getValue(),sl[a].getIndex());
				a++;
				}
			else
				{
				fina[i]=new Data(sr[b].getValue(),sr[b].getIndex());
				b++;
				}
			}
		return fina;
		}
	}
 class Data
	{
	private int val;
	private int index;
	public Data(int x,int y)
		{
		val=x;
		index=y;
		}
	public int getValue()
		{
		return this.val;
		}
	public int getIndex()
		{
		return this.index;
		}
	}


import java.util.*;
import java.lang.*;
public class A205
	{
	public static void main(String[] args)
		{
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		int i=0;
		Data a[] = new Data[n];
		for(i=0;i<n;i++)
			{
			a[i]=new Data(in.nextInt(),i+1);
			}
		a=MergeSort(a,0,n-1);
		if(a[0].getValue()!=a[1].getValue())
			{
			System.out.println(a[0].getIndex());
			}
		else
			{
			System.out.println("Still Rozdill");
			}
		}
	public static Data[] MergeSort(Data[] a,int low,int high)
		{
		if(low>=high)
			{
			return a;
			}
		else
			{
			int middle=(high+low)/2;
			Data[] left = new Data [middle-low+1];
			Data[] right = new Data [high-middle];
			int i=0,count=0;
			for(i=0;i<=middle-low;i++)
				{
				left[count]=a[i];count++;
				}
			count=0;
			for(i=middle+1-low;i<=high-low;i++)
				{
				right[count]=a[i];count++;
				}
			Data[] SortedLeft =MergeSort(left,low,middle);
			Data[] SortedRight =MergeSort(right,middle+1,high);
			return Merge(SortedLeft,SortedRight,low,high);
			}
		}
	public static Data[] Merge(Data[] sl,Data[] sr,int low,int high)
		{
		Data fina[]  = new Data[high-low+1];
		int i=0,middle =(high+low)/2;
		int a=0,b=0,alimit=middle-low+1,blimit=high-middle;
		int n=alimit+blimit;
		/*System.out.println("sl");
		for(i=0;i<alimit;i++)
			{
			int x = sl[i].getValue();
			int y = sl[i].getIndex();
			System.out.println(x+" "+y);
			}
		System.out.println("sr");
		for(i=0;i<blimit;i++)
			{
			int x = sr[i].getValue();
			int y = sr[i].getIndex();
			System.out.println(x+" "+y);
			}*/
		for(i=0;i<n;i++)
			{
			if(a!=alimit&&(b==blimit||(sl[a].getValue()<=sr[b].getValue()&&a<alimit)))
				{
				fina[i]=new Data(sl[a].getValue(),sl[a].getIndex());
				a++;
				}
			else
				{
				fina[i]=new Data(sr[b].getValue(),sr[b].getIndex());
				b++;
				}
			}
		return fina;
		}
	}
 class Data
	{
	private int val;
	private int index;
	public Data(int x,int y)
		{
		val=x;
		index=y;
		}
	public int getValue()
		{
		return this.val;
		}
	public int getIndex()
		{
		return this.index;
		}
	}


import java.util.*;
import java.lang.*;
public class A205
	{
	public static void main(String[] args)
		{
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		int i=0;
		Data a[] = new Data[n];
		for(i=0;i<n;i++)
			{
			a[i]=new Data(in.nextInt(),i+1);
			}
		a=MergeSort(a,0,n-1);
		if(n==1)
			{
			System.out.println("1");System.exit(0);
			}
		if(a[0].getValue()!=a[1].getValue())
			{
			System.out.println(a[0].getIndex());
			}
		else
			{
			System.out.println("Still Rozdil");
			}
		}
	public static Data[] MergeSort(Data[] a,int low,int high)
		{
		if(low>=high)
			{
			return a;
			}
		else
			{
			int middle=(high+low)/2;
			Data[] left = new Data [middle-low+1];
			Data[] right = new Data [high-middle];
			int i=0,count=0;
			for(i=0;i<=middle-low;i++)
				{
				left[count]=a[i];count++;
				}
			count=0;
			for(i=middle+1-low;i<=high-low;i++)
				{
				right[count]=a[i];count++;
				}
			Data[] SortedLeft =MergeSort(left,low,middle);
			Data[] SortedRight =MergeSort(right,middle+1,high);
			return Merge(SortedLeft,SortedRight,low,high);
			}
		}
	public static Data[] Merge(Data[] sl,Data[] sr,int low,int high)
		{
		Data fina[]  = new Data[high-low+1];
		int i=0,middle =(high+low)/2;
		int a=0,b=0,alimit=middle-low+1,blimit=high-middle;
		int n=alimit+blimit;
		/*System.out.println("sl");
		for(i=0;i<alimit;i++)
			{
			int x = sl[i].getValue();
			int y = sl[i].getIndex();
			System.out.println(x+" "+y);
			}
		System.out.println("sr");
		for(i=0;i<blimit;i++)
			{
			int x = sr[i].getValue();
			int y = sr[i].getIndex();
			System.out.println(x+" "+y);
			}*/
		for(i=0;i<n;i++)
			{
			if(a!=alimit&&(b==blimit||(sl[a].getValue()<=sr[b].getValue()&&a<alimit)))
				{
				fina[i]=new Data(sl[a].getValue(),sl[a].getIndex());
				a++;
				}
			else
				{
				fina[i]=new Data(sr[b].getValue(),sr[b].getIndex());
				b++;
				}
			}
		return fina;
		}
	}
 class Data
	{
	private int val;
	private int index;
	public Data(int x,int y)
		{
		val=x;
		index=y;
		}
	public int getValue()
		{
		return this.val;
		}
	public int getIndex()
		{
		return this.index;
		}
	}


import java.io.OutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.InputMismatchException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Diego Huerfano ( diego.link )
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskA solver = new TaskA();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskA {
    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int n=in.readInt();
        int ai;
        int min=Integer.MAX_VALUE, cnt=0, ind=-1;
        for( int i=0; i<n; i++ ){
            ai=in.readInt();
            if( ai<min ) {
                min=ai;
                cnt=1;
                ind=i+1;
            } else if( ai==min ) {
                cnt++;
            }
        }
        if( cnt==1 ) out.println( ind );
        else out.println("Still Rozdil");
    }
}

class InputReader {

    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;

    public InputReader(InputStream stream) {
        this.stream = stream;
    }

    public int read() {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    public int readInt() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        int res = 0;
        do {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public boolean isSpaceChar(int c) {
        if (filter != null)
            return filter.isSpaceChar(c);
        return isWhitespace(c);
    }

    public static boolean isWhitespace(int c) {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    public interface SpaceCharFilter {
        public boolean isSpaceChar(int ch);
    }
}


import java.io.PrintStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.BufferedInputStream;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Diego Huerfano ( diego.link )
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskA solver = new TaskA();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskA {
    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int n=in.nextInt();
        int ai;
        int min=Integer.MAX_VALUE, cnt=0, ind=-1;
        for( int i=0; i<n; i++ ){
            ai=in.nextInt();
            if( ai<min ) {
                min=ai;
                cnt=1;
                ind=i+1;
            } else if( ai==min ) {
                cnt++;
            }
        }
        if( cnt==1 ) out.println( ind );
        else out.println("Still Rozdil");
    }
}

class InputReader {

    private BufferedInputStream inp;
    private int offset;
    private final int size=5120000;
    private byte buff[];

    public InputReader( InputStream in ) {
        inp = new BufferedInputStream( in );
        buff=new byte[size];
        offset=0;
        try {
            inp.read( buff, 0, size );
        }catch (Exception e ){
            System.err.println( "error" );
        }
    }

    private void copyLeftovers() {

        int j = 0;
        for ( ; offset<size; j++, offset++ )
            buff[j] = buff[offset];
        // and now fill the buffer
        try {
            inp.read( buff, j, size - j );
        }catch (Exception e ){
            System.err.println( "error" );
        }
    }

    public int nextInt() {

        int parsedInt=0, by=1;
        int i=offset;
        // skip any non digits
        while ( i<size && ( (buff[i]<'0' || buff[i]>'9') && buff[i]!='-' ) ) i++;
        // read digits and parse number
        if( i<size && buff[i]=='-' ) {
            by=-1;
            i++;
        }
        while( i<size && buff[i]>='0' && buff[i]<='9') {
            parsedInt*=10;
            parsedInt+=buff[i]-'0';
            i++;
        }
        // check if we reached end of buffer
        if ( i==size ) {
            // copy leftovers to buffer start
            copyLeftovers();
            // and attempt to parse int again
            offset = 0;
            parsedInt = nextInt();
        } else offset=i;
        return parsedInt*by;
    }

    }


package diegolink;

import diegolink.utils.io.InputReader;
import java.io.PrintWriter;

public class TaskA {
    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int n=in.nextInt();
        int ai;
        int min=Integer.MAX_VALUE, cnt=0, ind=-1;
        for( int i=0; i<n; i++ ){
            ai=in.nextInt();
            if( ai<min ) {
                min=ai;
                cnt=1;
                ind=i+1;
            } else if( ai==min ) {
                cnt++;
            }
        }
        if( cnt==1 ) out.println( ind );
        else out.println("Still Rozdil");
    }
}


import java.util.Scanner;

public class Elefent {
    public static void main(String[] args) {
        int n,count=0,counter=0;
        Scanner sc= new Scanner(System.in);
        n=sc.nextInt();
        int [] no=new int[n];
        for (int i=0;i<n;i++)
            no[i]=sc.nextInt();
        int min=no[0];
        if (n>1)
        {
            for (int i =1;i<n;i++)
            {
              if (min >no[i])
              {
                  min=no[i];
                  counter=i;
              }

            }
            for (int i=0;i<n;i++)
            {
                if(min==no[i])
                    count++;
            }
            if (count-1==0)
                System.out.println(counter+1);
            else
                System.out.println("Still Rozdil");
        }

        else
            System.out.println(n);
    }
}


import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;

public class Test2 {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
	int n=input.nextInt();
 int min=Integer.MAX_VALUE;
 boolean f=true;
 int index=0;
 for(int i=0;i<n;i++){
	 int x=input.nextInt();
	 if(min==x){
		 f=false;
		 continue;
	 }
	if(x<min){
		f=true;
		min=x;
		index=i;
	}
 }

 if(f)
	System.out.println(index+1);
 else
	 System.out.println("Still Rozdil");
	}
}


import java.util.*;
import java.io.*;
import java.awt.Point;
import java.math.BigDecimal;
import java.math.BigInteger;

import static java.lang.Math.*;

// Solution is at the bottom of code

public class A implements Runnable{

	final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;

	BufferedReader in;
	OutputWriter out;
	StringTokenizer tok = new StringTokenizer("");

	public static void main(String[] args){
		new Thread(null, new A(), "", 128 * (1L << 20)).start();
	}

	/////////////////////////////////////////////////////////////////////

	void init() throws FileNotFoundException{
		Locale.setDefault(Locale.US);

		if (ONLINE_JUDGE){
			in = new BufferedReader(new InputStreamReader(System.in));
			out = new OutputWriter(System.out);
		}else{
			in = new BufferedReader(new FileReader("input.txt"));
			out = new OutputWriter("output.txt");
		}
	}

	////////////////////////////////////////////////////////////////

	long timeBegin, timeEnd;

	void time(){
		timeEnd = System.currentTimeMillis();
		System.err.println("Time = " + (timeEnd - timeBegin));
	}

	void debug(Object... objects){
		if (ONLINE_JUDGE){
			for (Object o: objects){
				System.err.println(o.toString());
			}
		}
	}

	/////////////////////////////////////////////////////////////////////

	public void run(){
		try{
			timeBegin = System.currentTimeMillis();
			Locale.setDefault(Locale.US);

			init();
			solve();

			out.close();
			time();
		}catch (Exception e){
			e.printStackTrace(System.err);
			System.exit(-1);
		}
	}

	/////////////////////////////////////////////////////////////////////

	String delim = " ";

	String readString() throws IOException{
		while(!tok.hasMoreTokens()){
			try{
				tok = new StringTokenizer(in.readLine());
			}catch (Exception e){
				return null;
			}
		}

		return tok.nextToken(delim);
	}

	String readLine() throws IOException{
		return in.readLine();
	}

	/////////////////////////////////////////////////////////////////

	final char NOT_A_SYMBOL = '\0';

	char readChar() throws IOException{
		int intValue = in.read();

		if (intValue == -1){
			return NOT_A_SYMBOL;
		}

		return (char) intValue;
	}

	char[] readCharArray() throws IOException{
		return readLine().toCharArray();
	}

	/////////////////////////////////////////////////////////////////

	int readInt() throws IOException{
		return Integer.parseInt(readString());
	}

	int[] readIntArray(int size) throws IOException{
		int[] array = new int[size];

		for (int index = 0; index < size; ++index){
			array[index] = readInt();
		}

		return array;
	}

	///////////////////////////////////////////////////////////////////

	long readLong() throws IOException{
		return Long.parseLong(readString());
	}

	long[] readLongArray(int size) throws IOException{
		long[] array = new long[size];

		for (int index = 0; index < size; ++index){
			array[index] = readLong();
		}

		return array;
	}

	////////////////////////////////////////////////////////////////////

	double readDouble() throws IOException{
		return Double.parseDouble(readString());
	}

	double[] readDoubleArray(int size) throws IOException{
		double[] array = new double[size];

		for (int index = 0; index < size; ++index){
			array[index] = readDouble();
		}

		return array;
	}

	////////////////////////////////////////////////////////////////////

	BigInteger readBigInteger() throws IOException {
		return new BigInteger(readString());
	}

	BigDecimal readBigDecimal() throws IOException {
		return new BigDecimal(readString());
	}

	/////////////////////////////////////////////////////////////////////

	Point readPoint() throws IOException{
		int x = readInt();
		int y = readInt();
		return new Point(x, y);
	}

	Point[] readPointArray(int size) throws IOException{
		Point[] array = new Point[size];

		for (int index = 0; index < size; ++index){
			array[index] = readPoint();
		}

		return array;
	}

	/////////////////////////////////////////////////////////////////////

	List<Integer>[] readGraph(int vertexNumber, int edgeNumber)
	throws IOException{
		@SuppressWarnings("unchecked")
		List<Integer>[] graph = new List[vertexNumber];

		for (int index = 0; index < vertexNumber; ++index){
			graph[index] = new ArrayList<Integer>();
		}

		while (edgeNumber-- > 0){
			int from = readInt() - 1;
			int to = readInt() - 1;

			graph[from].add(to);
			graph[to].add(from);
		}

		return graph;
	}

	/////////////////////////////////////////////////////////////////////

	static class IntIndexPair {

		static Comparator<IntIndexPair> increaseComparator = new Comparator<A.IntIndexPair>() {

			@Override
			public int compare(IntIndexPair indexPair1, IntIndexPair indexPair2) {
				int value1 = indexPair1.value;
				int value2 = indexPair2.value;

				if (value1 != value2) return value1 - value2;

				int index1 = indexPair1.index;
				int index2 = indexPair2.index;

				return index1 - index2;
			}
		};

		static Comparator<IntIndexPair> decreaseComparator = new Comparator<A.IntIndexPair>() {

			@Override
			public int compare(IntIndexPair indexPair1, IntIndexPair indexPair2) {
				int value1 = indexPair1.value;
				int value2 = indexPair2.value;

				if (value1 != value2) return -(value1 - value2);

				int index1 = indexPair1.index;
				int index2 = indexPair2.index;

				return index1 - index2;
			}
		};

		int value, index;

		public IntIndexPair(int value, int index) {
			super();
			this.value = value;
			this.index = index;
		}
	}

	IntIndexPair[] readIntIndexArray(int size) throws IOException {
		IntIndexPair[] array = new IntIndexPair[size];

		for (int index = 0; index < size; ++index) {
			array[index] = new IntIndexPair(readInt(), index);
		}

		return array;
	}

	/////////////////////////////////////////////////////////////////////

	static class OutputWriter extends PrintWriter{

		final int DEFAULT_PRECISION = 12;

		int precision;
		String format, formatWithSpace;

		{
			precision = DEFAULT_PRECISION;

			format = createFormat(precision);
			formatWithSpace = format + " ";
		}

		public OutputWriter(OutputStream out) {
			super(out);
		}

		public OutputWriter(String fileName) throws FileNotFoundException {
			super(fileName);
		}

		public int getPrecision() {
			return precision;
		}

		public void setPrecision(int precision) {
			precision = max(0, precision);
			this.precision = precision;

			format = createFormat(precision);
			formatWithSpace = format + " ";
		}

		private String createFormat(int precision){
			return "%." + precision + "f";
		}

		@Override
		public void print(double d){
			printf(format, d);
		}

		public void printWithSpace(double d){
			printf(formatWithSpace, d);
		}

		public void printAll(double...d){
			for (int i = 0; i < d.length - 1; ++i){
				printWithSpace(d[i]);
			}

			print(d[d.length - 1]);
		}

		@Override
		public void println(double d){
			printlnAll(d);
		}

		public void printlnAll(double... d){
			printAll(d);
			println();
		}
	}

	/////////////////////////////////////////////////////////////////////

	int[][] steps = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};
	int[][] steps8 = {
			{-1, 0}, {1, 0}, {0, -1}, {0, 1},
			{-1, -1}, {1, 1}, {1, -1}, {-1, 1}
	};

	boolean check(int index, int lim){
		return (0 <= index && index < lim);
	}

	/////////////////////////////////////////////////////////////////////

	boolean checkBit(int mask, int bitNumber){
		return (mask & (1 << bitNumber)) != 0;
	}

	/////////////////////////////////////////////////////////////////////

	void solve() throws IOException{
		int n = readInt();

		IntIndexPair[] cities = readIntIndexArray(n);
		Arrays.sort(cities, IntIndexPair.increaseComparator);

		if (n > 1 && cities[0].value == cities[1].value) {
			out.println("Still Rozdil");
		} else {
			int answer = cities[0].index + 1;
			out.println(answer);
		}
	}
}


import java.util.Scanner;

public class A {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int min = Integer.MAX_VALUE;
        int idx = -1;
        for (int i=0; i<n; i++) {
            int dist = sc.nextInt();
            if (dist < min) {
                min = dist;
                idx = i;
            } else if (dist == min) {
                idx = -1;
            }
        }
        if (idx == -1) {
            System.out.println("Still Rozdil");
        } else {
            System.out.println(Integer.toString(idx+1));
        }
    }

}


import java.util.Scanner;

public class A {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int min = Integer.MAX_VALUE;
		int idx = -1;
		for (int i=0; i<n; i++) {
			int dist = sc.nextInt();
			if (dist < min) {
				min = dist;
				idx = i;
			} else if (dist == min) {
				idx = -1;
			}
		}
		if (idx == -1) {
			System.out.println("Still Rozdil");
		} else {
			System.out.println(Integer.toString(idx+1));
		}
	}

}


package div2_129;

import java.util.Scanner;

public class A {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int min = Integer.MAX_VALUE;
		int idx = -1;
		for (int i=0; i<n; i++) {
			int dist = sc.nextInt();
			if (dist < min) {
				min = dist;
				idx = i;
			} else if (dist == min) {
				idx = -1;
			}
		}
		if (idx == -1) {
			System.out.println("Still Rozdil");
		} else {
			System.out.println(Integer.toString(idx+1));
		}
	}

}


import java.util.Scanner;

/**
 * @author Son-Huy TRAN
 *
 */
public class P205A_LittleElephantAndRozdil {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);

		// read the inputs
		int n = scanner.nextInt();
		int[] costs = new int[n];

		for (int i = 0; i < n; i++) {
			costs[i] = scanner.nextInt();
		}

		scanner.close();

		int min = Integer.MAX_VALUE;
		int imin = -1;
		int countMin = 0;

		for (int i = 0; i < n; i++) {
			if (costs[i] < min) {
				min = costs[i];
				imin = i;
				countMin = 1;
			} else if (costs[i] == min) {
				countMin++;
			}
		}

		if (countMin > 1) {
			System.out.println("Still Rozdil");
		} else {
			System.out.println(imin + 1);
		}
	}
}


import java.io.OutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.InputMismatchException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author George Marcus
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		StreamInputReader in = new StreamInputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskA solver = new TaskA();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskA {
	public void solve(int testNumber, StreamInputReader in, PrintWriter out) {
        int N = in.readInt();
        int[] D = new int[N];
        for(int i = 0; i < N; i++)
            D[i] = in.readInt();
        int min = Integer.MAX_VALUE;
        for(int i = 0; i < N; i++)
            min = Math.min(min, D[i]);
        int cnt = 0;
        int pmin = -1;
        for(int i = 0; i < N; i++)
            if(D[i] == min) {
                cnt++;
                pmin = i;
            }
        if(cnt == 1)
            out.print(pmin + 1);
        else
            out.print("Still Rozdil");
	}
}

class StreamInputReader extends InputReader {
    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar, numChars;

    public StreamInputReader(InputStream stream) {
        this.stream = stream;
    }

    public int read() {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    }

abstract class InputReader {

    public abstract int read();

    public int readInt() {
        return Integer.parseInt(readString());
    }

    public String readString() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        StringBuffer res = new StringBuffer();
        do {
            res.appendCodePoint(c);
            c = read();
        } while (!isSpaceChar(c));
        return res.toString();
    }

    private boolean isSpaceChar(int c) {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    }


import java.util.*;

import static java.lang.System.out;

/**
 * @author artyom
 */
public class LittleElephantAndRozdil {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Map<Integer, Integer> counts = new HashMap<>(n);
        int min = Integer.MAX_VALUE, minIndex = 0;
        for (int i = 0; i < n; i++) {
            int dist = sc.nextInt();
            if (dist < min) {
                min = dist;
                minIndex = i;
            }
            if (counts.containsKey(dist)) {
                counts.put(dist, counts.get(dist) + 1);
            } else {
                counts.put(dist, 1);
            }
        }
        out.println(counts.get(min) == 1 ? minIndex + 1 : "Still Rozdil");
    }
}


import java.util.Arrays;
import java.util.Scanner;
public class codeforces205A {
    public static void main(String args[]){
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int [] arr1 = new int [n];
        int [] arr2 = new int [n];
        for(int i=0; i<n; i++){
            arr1[i]=input.nextInt();
            arr2[i]=arr1[i];
        }
        Arrays.sort(arr1);
            for(int i=0; i<n; i++){
                if(arr1[0]==arr1[1]){
                    System.out.println("Still Rozdil");
                    break;
                }
                int x = arr1[0];
                if(arr2[i]==x){
                System.out.println(i+1);
                break;
                }
            }
     }
}


import java.util.Arrays;
import java.util.Scanner;
public class codeforces205A {
    public static void main(String args[]){
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int [] arr1 = new int [n];
        int [] arr2 = new int [n];
        for(int i=0; i<n; i++){
            arr1[i]=input.nextInt();
            arr2[i]=arr1[i];
        }
        Arrays.sort(arr1);
        if(n==1){
            System.out.println("1");
        }else{
            for(int i=0; i<n; i++){
                if(arr1[0]==arr1[1]){
                    System.out.println("Still Rozdil");
                    break;
                }
                int x = arr1[0];
                if(arr2[i]==x){
                System.out.println(i+1);
                break;
                }
            }
        }
     }
}


import java.util.Scanner;

public class practice {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		int m = Integer.MAX_VALUE;
		int count = 0;
		int index = -1;
		for(int i = 0; i<n; i++) {
			int temp = sc.nextInt();
			if(m == temp) count++;
			if(m > temp) {
				m = temp;
				index = i+1;
			}
		}
		if(count > 0) System.out.println("Still Rozdil");
		else
			System.out.println(index);
	}
}


import java.util.Scanner;

public class practice {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		int m = Integer.MAX_VALUE;
		int count = 0;
		int index = -1;
		for(int i = 0; i<n; i++) {
			int temp = sc.nextInt();
			if(m == temp) count++;
			else if(m > temp) {
				m = temp;
				index = i+1;
				count = 0;
			}
		}
		if(count > 0) System.out.println("Still Rozdil");
		else
			System.out.println(index);
	}
}