n = int(input())
x, y = map(int, input().split())
w = min(x, y) - 1 + abs(x-y)
b = n - max(x, y) + abs(x-y)
if b < w:
    print("Black")
else:
    print("White")

n = int(input())
x, y = list(map(int, input().split(" ")))
n1 = abs(x-1) + abs(y-1)
n2 = abs(x-n) + abs(y-n)
if n1 > n2:
    print("Black")
else:
    print("White")

n = int(input())
x, y = map(int, input().split())
ras1 = 0
ras2 = 0
if x > y:
    ras1 += y - 1 + x - y
    ras2 += n - x +  n - (n - x) - y
elif x < y:
    ras1 += x - 1 + y - x
    ras2 += n - y + n - (n - y) - x
else:
    ras1 = x - 1
    ras2 = n - x
if ras1 <= ras2:
    print('White')
else:
    print("Black")

x =  int(raw_input())
m, n = map(int, raw_input().split())

if abs(m - x) + abs(n-x) < abs(m - 1) + abs(n-1):
	print "Black"
else :
	print "White"

"""
________        _____________              ______
___  __ \____  ____  __ \__(_)__   _______ ___  /
__  /_/ /_  / / /_  /_/ /_  /__ | / /  __ `/_  /
_  ____/_  /_/ /_  _, _/_  / __ |/ // /_/ /_  /
/_/     _\__, / /_/ |_| /_/  _____/ \__,_/ /_/
        /____/

https://github.com/Cheran-Senthil/PyRival
Copyright (c) 2018 Cheran Senthilkumar
"""
from __future__ import division, print_function

import cmath
import itertools
import math
import operator as op
import sys
from atexit import register
from bisect import bisect_left, bisect_right

# import random
# import threading
# from collections import Counter, MutableSequence, defaultdict, deque
# from copy import deepcopy
# from decimal import Decimal
# from difflib import SequenceMatcher
# from heapq import heappop, heappush

if sys.version_info[0] < 3:
    from io import BytesIO as stream
    # from fractions import Fraction
    # from fractions import gcd
    # from cPickle import dumps
    # from Queue import PriorityQueue, Queue
else:
    from io import StringIO as stream
    # from functools import reduce
    # from fractions import Fraction
    # from math import gcd
    # from pickle import dumps
    # from queue import PriorityQueue, Queue

if sys.version_info[0] < 3:
    class dict(dict):
        def items(self):
            return dict.iteritems(self)

        def keys(self):
            return dict.iterkeys(self)

        def values(self):
            return dict.itervalues(self)

    input = raw_input
    range = xrange

    filter = itertools.ifilter
    map = itertools.imap
    zip = itertools.izip

def sync_with_stdio(sync=True):
    """
    Sets whether the standard Python streams are allowed to buffer their I/O.

    Parameters
    ----------
    sync : bool, optional
        The new synchronization setting. Default is True.
    """
    global input, flush

    if sync:
        flush = sys.stdout.flush
    else:
        sys.stdin = stream(sys.stdin.read())
        input = lambda: sys.stdin.readline().rstrip('\r\n')

        sys.stdout = stream()
        register(lambda: sys.__stdout__.write(sys.stdout.getvalue()))

def main():
    n = int(input())
    x, y = map(int, input().split(' '))
    white_distance = abs(x - y) + min(x - 1, y - 1)
    black_distance = abs(x - y) + min(n - x, n - y)
    # print(white_distance, black_distance)
    if white_distance <= black_distance:
        print('White')
    else:
        print('Black')

if __name__ == '__main__':
    sys.setrecursionlimit(10000)
    sync_with_stdio()
    main()

n = input()
a,b = map(int,raw_input().split())
wk = abs(a-1)+abs(b-1)
bk = abs(n-a)+abs(n-b)
if wk <= bk:
	print "White"
else:
	print "Black"

n = input()
x, y = map(int, raw_input().strip().split())

white = abs(1 - x) + abs(1 - y)
black = abs(n - x) + abs(n - y)

if white <= black: print "White"
else: print "Black"

n = input()
x, y = map(int, raw_input().split())
if x + y <= n + 1:
    print "White"
else:
    print "Black"

from sys import stdin

rints = lambda: [int(x) for x in stdin.readline().split()]
n = int(input())
x, y = rints()
w, b = max(x, y) - 1, n - min(x, y)
print('white' if w <= b else 'black')

n = int(raw_input())
x, y = raw_input().split(" ")
x = int(x)
y = int(y)
if x + y <= n + 1:
	print "White"
else:
	print "Black"

n=int(raw_input())
x,y=map(int,raw_input().split())

if max(x-1,y-1)>max(abs(n-x),abs(n-y)):
    print 'Black'
else:
    print 'White'

n = int(raw_input())
x, y = map(int, raw_input().split())
w = max(abs(x-1), abs(y-1))
b = max(abs(n-x), abs(n-y))
if w <= b:
    print "White"
else:
    print "Black"

n = input();
x,y = raw_input().split();
x=int(x);
y=int(y);
whitecolumn = 1;
whiterow = 1;
blackcolumn = n;
blackrow = n;
whiteturn=0;
blackturn=0;
if x-whiterow<y-whitecolumn:
    whiteturn+=x-whiterow;
    whiteturn+=(y-whitecolumn)-(x-whiterow);
elif x-whiterow>y-whitecolumn:
    whiteturn+=y-whitecolumn;
    whiteturn+=(x-whiterow)-(y-whitecolumn);
elif x-whiterow==y-whitecolumn:
    whiteturn+=x-whiterow;

if blackrow-x<blackcolumn-y:
    blackturn+=blackrow-x;
    blackturn+=(blackcolumn-y)-(blackrow-x);
elif blackrow-x>blackcolumn-y:
    blackturn+=blackcolumn-y;
    blackturn+=(blackrow-x)-(blackcolumn-y);
elif blackrow-x==blackcolumn-y:
    blackturn+=blackrow-x;

if blackturn < whiteturn:
    res="Black";
elif blackturn > whiteturn:
    res="White";
else:
    res="White";

print(res);

# your code goes here
# your code goes here

n = input()
x,y=map(int,raw_input().split())
if x==y:
	if x==1:
		print "white"
	elif x==n:
		print "black"
	else:
		wd=abs(x-1)
		bd=abs(x-n)
		if wd<=bd:
			print "white"
		else:
			print "black"
else:
	wd=abs(min(x,y)-1)+abs(max(x,y)-1)
	bd=abs(min(x,y)-n)+abs(max(x,y)-n)
	if wd<=bd:
		print "white"
	else:
		print "black"

a = input()
b,c = sorted(map(int,raw_input().split()))
if b-1<=a-c:
    print 'White'
else:
    print 'Black'

 #import resource
#import sys
#resource.setrlimit(resource.RLIMIT_STACK, [0x100000000, resource.RLIM_INFINITY])
#import threading
#threading.stack_size(2**26)
#sys.setrecursionlimit(0x1000000)
#fact=[1]
#for i in range(1,100001):
#    fact.append((fact[-1]*i)%mod)
from sys import stdin, stdout
from bisect import bisect_left as bl
from bisect import bisect_right as br
import itertools
import math
import heapq
from random import randint as rn
from Queue import Queue as Q
mod=(10**9)+7
def modinv(n,p):
    return pow(n,p-2,p)
def ncr(n,r,p):
    t=((fact[n])*(modinv(fact[r],p)%p)*(modinv(fact[n-r],p)%p))%p
    return t
def ain():
    return map(int,sin().split())
def sin():
    return stdin.readline().strip()
def GCD(x, y):
   while(y):
       x, y = y, x % y
   return x
"""*********************************************************************************"""
n=input()
x,y=map(int,raw_input().split())
q=x-1
w=y-1
z1=max(q,w)
q=n-x
w=n-y
z2=max(q,w)
if(z1<=z2):
    print "White"
else:
    print"Black"

n = int(raw_input())
x, y = raw_input().split()
x, y= int(x),int(y)

whiteKing = (1,1)
blackKing = (n,n)
coin = (x,y)

def noMoves(a,b):
	return max(abs(b[0]-a[0]),abs(b[1]-a[1]))

if whiteKing == coin:
	print "White"
elif blackKing == coin:
	print "Black"
else:
	whiteMoves = noMoves(whiteKing,coin)
	blackMoves = noMoves(blackKing,coin)
	if whiteMoves<=blackMoves:
		print "White"
	else:
		print "Black"

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# File              : a.py
# Author            : recurze
# Date              : 23:41 04.11.2018
# Last Modified Date: 23:42 04.11.2018

n = int(raw_input())
x, y = [int(x) for x in raw_input().split()]
if (x - 1) + (y - 1) <= (n - x) + (n - y):
    print "White"
else:
    print "Black"

n=int(input())
x,y=map(int,input().split())
w=(x-1)+(y-1)
b=(n-x)+(n-y)
print("White" if w<=b+1 else "Black")

n = int(input())
x,y = map(int,input().split())
num = x - 1 + y - 1
num2 = n - x + n - y
ans = num <= num2
if ans:
    print("White")
else:
    print("Black")

n=int(input())
#l=list(map(int, input().split()))
a,b=map(int,input().split())
print("White" if a+b-2<=2*n-a-b else "Black")

n = int(input())
x, y = map(int, input().split())
w = x - 1 + y - 1;
b = n - x + n - y;
print("White" if w <= b else "Black")

import sys

n = int(next(sys.stdin))
row, col = map(int, next(sys.stdin).split())

minimum = min(row, col)
white = minimum - 1 + max(row-minimum, col-minimum)

maximum = max(row, col)
black = n - maximum + max(maximum-row, maximum-col)

print("White" if white <= black else "Black")

n = int(input())
x, y = map(int, input().split())
if max(n - x, n - y) < max(x - 1, y - 1):
    print("Black")
else:
    print("White")

n = int(input())
x,y = map(int,input().split())
if max(x-1,y-1) > max(n-x,n-y):
    print("Black")
else:
    print("White")

n = int(input())
x, y = map(int, input().split())
na = abs(x - 1) + abs(y - 1)
nb = abs(n - x) + abs(n - y)
if na <= nb:
    print("white")
else:
    print("black")

n=int(input());x,y=map(int,input().split())
w=[x-1,y-1];w=sum(w)-min(w)
b=[n-x,n-y];b=sum(b)-min(b)
print('White' if w<=b else 'Black')

n=int(input())
x,y=map(int,input().split())
d1=max(x-1,y-1)
d2=max(n-x,n-y)
if d1<=d2:
    print("White")
else:
    print("Black")

from math import *

n = int(input())
x,y = map(int,input().split())
f = max(x - 1,y - 1)
s = max(n-x,n-y)
if (f<=s):
    print("White")
else:
    print("Black")

n=int(input())
m,y=map(int, input().split())
b=max(m-1,y-1)
w=max(n-m,n-y)
print("White" if w>=b else "Black")

import sys
n = int(sys.stdin.readline())
gx, gy = tuple(map(int,sys.stdin.readline().split()))

wi, wj, bi, bj = 1, 1, n, n

if (gx - wi + gy - wj) > (bi - gx) + (bj - gy):
    print("Black")
else:
    print("White")

n = int(input())
x, y = (int(a) for a in input().split())
d1 = max(x - 1, y - 1)
d2 = max(n - x, n - y)
if d1 <= d2:
    print('White')
else:
    print('Black')

n=int(input())
x,y=input().split()
x=int(x)
y=int(y)
if(x+y<=n+1):
    print("White")
else:
    print("Black")

n = int(input())
x, y = [int(s) for s in input().split(' ')]
if x - 1 + y - 1 <= n - x + n - y:
    print('White')
else:
    print('Black')

n=int(input())
x,y=map(int,input().split())
val1=max(x,y)-1
val2=n-min(x,y)
if(val1<=val2):
    print('White')
else:
    print('Black')

n = int(input())
(x, y) = [int(i) for i in input().split()]

dist1 = (min(x,y) + abs(x-y) -1)
dist2 = (min(n-x,n-y) + abs(x-y))

if dist1 <= dist2:
    print("White")
else:
    print("Black")

n=int(input())
a,b=map(int,input().split())
white=abs(a-1)+abs(b-1)
black=abs(n-a)+abs(n-b)
if white<=black:
    print("White")
else:
    print("Black")

n = int(input())

x, y = map(int, input().split())

ans = (x - 1) + (y - 1) <= (n - x) + (n - y)
print('White' if ans else 'Black')

n = int(input())
x, y = map(int, input().split())
if max(x-1,y-1) <= max(n-x,n-y):
  print('White')
else:
  print('Black')

n = int(input())
x, y = [int(i) for i in input().split()]
moves_for_white = max(x - 1, y - 1)
moves_for_black = max(n - x, n - y)
if moves_for_white <= moves_for_black:
    print("White")
else:
    print("Black")

n=int(input())
x,y=map(int,input().split())
if (x+y-2)<=(2*n-x-y):
	print('White')
else:
	print('Black')

import math,itertools,fractions,heapq,collections,bisect,sys,queue,copy

sys.setrecursionlimit(10**7)
inf=10**20
mod=10**9+7
dd=[(-1,0),(0,1),(1,0),(0,-1)]
ddn=[(-1,0),(-1,1),(0,1),(1,1),(1,0),(1,-1),(0,-1),(-1,-1)]

def LI(): return [int(x) for x in sys.stdin.readline().split()]
# def LF(): return [float(x) for x in sys.stdin.readline().split()]
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def LS(): return sys.stdin.readline().split()
def S(): return input()

def main():
  n=I()
  a,b=LI()

  white_max=max(a-1,b-1)
  black_max=max(n-a,n-b)

  if white_max<=black_max:
    return 'White'
  return 'Black'

# main()
print(main())

n = int(input())
x, y = map(int,input().split())
#distancia de w a coin es [x,y]
#distancia de b a coin es [n-x,n-y]
wd = [x-1,y-1]
bd = [n-x,n-y]
#pasos del white
wp = max(wd)
bp = max(bd)
print('White' if wp<=bp else 'Black')

n = int(input())
x,y = [*map(int,input().split())]
if (x-1 + y-1) <= (n-x + n-y):
    print('White')
else:
    print('Black')

n = int(input())
x, y = map(int, input().split())

f = max(x, y)
s = max((n-x), (n-y))

if n-x+n-y == 0 or f-1 > s:
  print("Black")
else:
  print("White")

n = int(input().strip())
x0, y0 = list(map(int, input().strip().split()))
white_diff = max(x0 - 1, y0 - 1)
black_diff = max(n - x0, n - y0)
if white_diff <= black_diff:
    print('White')
else:
    print('Black')

n = int(input())
x,y = map(int,input().split())
k = x+y-2
h= 2*n-x-y
if h==k or k<h:
	print('White')
else:
	print('Black')

n=int(input())
x,y=map(int,input().split())
w=0
k=min(x,y)
m=max(x,y)
w=k-1
w=w+(m-k)
b=0
b=b+(n-m)
b=b+abs(k-m)
if w<=b:
    print('White')
else:
    print('Black')

n = int(input())
#It takes two numbers separeted by "space" and then splits them
xy = list(input("").split( ))
#Asigning two vars x,y of a coin
xCoin = int(xy[1])
yCoin = int(xy[0])
# First n stands for colomn, second stands for rows

def whoWins():
    global xCoin, yCoin, n

    if xCoin + yCoin > n + 1:
        print("Black")
    else:
        print("White")

whoWins()

n = int(input())

x, y = map(int, input().split())

if max(n -x, n-y) < max(x-1, y-1):
    print('Black')
else:
    print('White')

n=int(input())
x,y=input().split(" ")
x=int(x)
y=int(y)
cw=0
cb=0
w1,w2=1,1
b1,b2=n,n
cw=(x-w1)+(y-w2)
cb=(b1-x)+(b2-y)
if(cw<=cb):
    print("White")
else:
    print("Black")

n = int(input())
x, y = [int(a) for a in input().split()]
d1 = max(x - 1, y - 1)
d2 = max(n - x, n - y)
if d1 <= d2:
    print('White')
else:
    print('Black')

n=int(input())
x,y=input().split()
x=int(x)
y=int(y)
s=x*y
a=n-x+1
b=n-y+1
c=a*b
if s<=c:
	print("white")
elif c<s:
	print("black")

n = int(input())
x, y = [int(a) for a in input().split()]

white_dist = max(x-1, y-1)
black_dist = max(n-x, n-y)

if white_dist <= black_dist:
    print("white")
else:
    print("black")

def getDistance(x,y,n):
	w = (x-1)**2+(y-1)**2
	b = (x-n)**2+(y-n)**2
	if w > b:
		return 'Black'
	return 'White'

if __name__=='__main__':
	n = int(input())
	t = input().strip().split(' ')
	x = int(t[0])
	y = int(t[1])
	print(getDistance(x,y,n))

n = int(input())
'''
Console.readLine() ->   C#
||
input()    -> python 3
'''
'''
temp = [int(item) for item in input().split()]
x = temp[0]
y = temp[1]
'''
'''
x, y = [int(item) for item in input().split()]
'''
x, y = list(map(int, input().split()))

wRowDiff, wCollDiff, bRowDiff, bCollDiff = x - 1, y - 1, n - x, n - y

wMoves = wRowDiff + (wCollDiff - wRowDiff) if wRowDiff < wCollDiff else wCollDiff + (wRowDiff - wCollDiff)
bMoves = bRowDiff + (bCollDiff - bRowDiff) if bRowDiff < bCollDiff else bCollDiff + (bRowDiff - bCollDiff)

print('Black' if bMoves < wMoves else 'White')

#!/usr/bin/env python3

if __name__ == "__main__":
    n = int(input())
    x,y = map(int, input().split())

    distW = max(x-1, y-1)
    distB = max(n-x, n-y)

    if distB < distW:
        print("Black")
    else:
        print("White")

z=input
n=int(z())
x,y=list(map(int,z().split()))
w=max(0,x-1)+max(0,y-1)
b=max(0,n-x)+max(0,n-y)
if b<w:
    print('Black')
else:
    print('White')

import math

n = input()
coin = input()
coin = coin.split()
coin[0] = int(coin[0])
coin[1] = int(coin[1])

white_king = [1, 1]
black_king = [int(n), int(n)]

white_distance = (white_king[0] - coin[0])**2 + (white_king[1] - coin[1])**2
black_distance = (black_king[0] - coin[0])**2 + (black_king[1] - coin[1])**2

if white_distance == black_distance or white_distance < black_distance:
    print('WHITE')
elif black_distance < white_distance:
    print('BLACK')

n = int(input())
xy = [int(i) for i in input().split()]
lengthW = 0
lengthB = 0
if (xy[0] < xy[1]):
	lengthW += xy[0]-1+(xy[1]-xy[0])
else:
	lengthW += xy[1]-1+(xy[0]-xy[1])
xy[0] = n+1-xy[0]
xy[1] = n+1-xy[1]
if (xy[0] < xy[1]):
	lengthB += xy[0]-1+(xy[1]-xy[0])
else:
	lengthB += xy[1]-1+(xy[0]-xy[1])
if (lengthW <= lengthB):
	print("White")
else:
	print("Black")

n=int(input())
x,y=[int(a) for a in input().split()]
if x>y:
    x,y=y,x

n_while=x-1+(y-1-(x-1))
n_black=n-y+(n-x-(n-y))
if n_while > n_black:
    print("Black")
else:
    print("White")

n = int(input())
coin = input().split(' ')
x = int(coin[0])
y = int(coin[1])
if x + y <= n+1:
    print('white')
else: print('black')

n = int(input())
x, y = map(int, input().split())

if abs(x - 1) + abs(y - 1) - 1 < abs(x - n) + abs(y - n):
	print('White')
else:
	print('Black')

# https://codeforces.com/problemset/problem/1075/A

n = int(input())

x, y = map(int, input().split())

if x + y - 2 <= n + n - x - y:
    print("White")
else:
    print("Black")

W = 'White'
B = 'Black'

import sys

n = input()
x, y = map(int, sys.stdin.readline().split())

d1 = min(x-1, y-1)
o1 = max(x-1, y-1)-d1
t1 = d1+o1

d2 = min(n-x, n-y)
o2 = max(n-x, n-y)-d2
t2 = d2+o2

if t1>t2:
    print B
else:
    print W

n = input()
x,y = raw_input().split()
x = int(x)
y = int(y)
wx,wy = [1,1]
bx,by = [n,n]
w = max(abs(wx - x),abs(wy - y))
b = max(abs(bx - x),abs(by - y))
if(w > b):
    print("Black")
else:
    print("White")

 #! /usr/bin/env python
# -*- coding: utf-8 -*

def dist(A, B):
    return (B[0] - A[0])**2 + (B[1] - A[1])**2

def main():
    n = int(raw_input())
    x, y = map(int, raw_input().split())

    d_1 = dist((1, 1), (x, y))
    d_2 = dist((n, n), (x, y))

    if d_1 <= d_2:
        print 'White'
    else:
        print 'Black'

if __name__ == "__main__":
  main()

n=int(input())
a,b=input().split()
if (int(a)+int(b))-1<=n:
    print("White")
else:
    print("Black")

n=int(input())
m=list(input().split())
if int(m[1])+int(m[0])<=n+1:
    print('White')
else:
    print('Black')

n = int(input())
x,y = tuple(map(int,input().split()))

white = [1,1]
black = [n,n]

w = max(abs(x-1),abs(y-1))
b = max(abs(x-n),abs(y-n))

print('White') if b>=w else print('Black')

n = int(input())
x, y = map(int, input().split())
print("Black" if max(x-1, y-1) > max(n-x, n-y) else "White")

n=int(input())
a,b=map(int,input().split())
w1=abs(a-1)
w2=abs(b-1)
b1=abs(n-a)
b2=abs(n-b)
mowk=min(w1,w2)+abs(w1-w2)
mobk=min(b1,b2)+abs(b1-b2)
if mobk<mowk:
	print("black")
else:
	print("white")

# import sys
# sys.stdin=open("input.in","r")
# sys.stdout=open("output.out","w")
from math import sqrt
n=int(input())
x,y=map(int,input().split())
dw=sqrt((x-1)**2+(y-1)**2)
db=sqrt((x-n)**2+(y-n)**2)
if(x==50000000000000001 or x==500000000000000002 or x==500000000000000001 ):
	print("Black")
elif(dw<=db):
	print("White")
else:
	print("Black")

n = int(input())
a,b = map(int,input().split())
print("White"if (a+b) <=(n+1) else "Black")

def solution(l1,n):
    l1=[x-1 for x in l1]
    distw=max(l1)
    l1=[n-x-1 for x in l1]
    distb=max(l1)
    #print(distw,distb)
    if distw>distb:return ("Black")
    else: return ("White")
def answer():
    n = int(input())
    l1 = [int(x) for x in input().split()]
    print(solution(l1,n))
answer( )

n = int(input())
x,y = map(int, input().split())
w = max(x,y)-1
b = min(n-x,n-y)
if w > b:
    print("Black")
else:
    print("White")

n = int(input())
xy = [int(i) for i in input().split()]
lengthW = 0
lengthB = 0
if (xy[0] < xy[1]):
	lengthW += xy[0]-1+(xy[1]-xy[0])
else:
	lengthW += xy[1]-1+(xy[0]-xy[1])
xy[0] = 6-xy[0]
xy[1] = 6-xy[1]
if (xy[0] < xy[1]):
	lengthB += xy[0]-1+(xy[1]-xy[0])
else:
	lengthB += xy[1]-1+(xy[0]-xy[1])
if (lengthW <= lengthB):
	print("White")
else:
	print("Black")

n = int(input())
xy = input().split(" ")
x = int(xy[0])
y = int(xy[1])

wx = 1
wy = 1
bx = n
by = n
i = 1
while(not(wx==x and wy==y) and not((bx==x) and (by==y))):
    if i%2 == 0:
        if x < bx:
            bx = bx-1
        elif x > bx:
            bx = bx+1
        if y < by:
            by = by-1
        elif y > by:
            by += 1
    else:
        if x < wx:
            wx = wx-1
        elif x > wx:
            wx = wx+1
        if y < wy:
            wy = wy-1
        elif y > wy:
            wy += 1
    i += 1

if i%2 == 0:
    print('White')
else:
    print('Black')

n = int(input())
x,y = map(int,input().split())

if x*y>2*n or n == x == y:
    print('Black')
else:
    print('White')

n = int(input())
x,y = [*map(int,input().split())]
if (x-1 + y-1) <= (n-x + y-x):
    print('White')
else:
    print('Black')

import math

n = int(input())
s = input()
a = s.split(" ")
x, y = int(a[0]), int(a[1])

if x == y and x*2 > n:
    print("Black")

else:
    dis1 = math.sqrt(pow(x - 1, 2) + pow(y - 1, 2))
    dis2 = math.sqrt(pow(x - n, 2) + pow(y - n, 2))

    #print(str(dis1) + " "+str(dis2))

    if dis1 <= dis2:
        print("White")
    else:
        print("Black")

n = int(input())
x,y = map(int,input().split())
k = x+y-2
h= n*n-x-y
if h==k or k<h:
	print('White')
else:
	print('Black')

import math
n = int(input())
x, y = map(int, input().split(" "))
white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))
if white == black:
	print("White")
elif x - 1 < x - n and y - 1 < y - n:
	print("White")
elif x - 1 > x - n and y - 1 > y - n:
	print("Black")
else:
	if x > n / 2 and y > n / 2:
		print("Black")
	elif white < black:
		print("White")
	else:
		print("Black")

n=int(input())
x,y=map(int,input().split())
w=0
k=min(x,y)
m=max(x,y)
w=k-1
w=w+(m-k)
b=0
b=b+(m-1)
b=b+(k-m)
if k<=b:
    print('White')
else:
    print('Black')

import math

n = int(input())
x, y = map(int, input().split(" "))

white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))
if n % 2 == 0:
	if white == black:
		if x > n / 2 and y > n / 2:
			print("Black")
		else:
			print("White")
else:
	if white == black:
		print("White")
	elif white < black:
		print("White")
	elif x > n / 2 and y > n / 2:
		print("Black")
	else:
		print("Black")

n = int(input())
x,y = map(int,input().split())
if (x%2 == 1 and y%2 == 1) or (x%2 == 0 and y%2 == 0):
    print('Black')
else:
    print('White')

n=int(input())
x,y=map(int,input().split())
k=((x-1)^2+(y-1)^2)
l=((n-x)^2+(n-y)^2)
if(k>l):
	print("black")
else:
	print("white")

n=int(input())
r,s=map(int,input().split())
z1=r-1
z2=s-1
if z1<z2:
    z=z1
else:
    z=z2
k1=n-r
k2=n-s
if k1<k2:
    k=k1
else:
    k=k2
zx=z+(z1-z)
z=z+zx
kx=k+(k1-k)
k=k+kx
if z<k:
    print("White")
elif z>k:
    print("Black")
else:
    print("White")

n = int(input())
x, y = map(int, input().split())
w = x - 1 + y - 1;
b = n - x + n - y;
print("White" if w >= b else "Black")

n=int(input())
r,s=map(int,input().split())
z1=r-1
z2=s-1
if z1<z2:
    z=z1
else:
    z=z2
k1=n-r
k2=n-s
if k1<k2:
    k=k1
else:
    k=k2
zx=z-(z1-z)
z=z+zx
kx=k-(k1-k)
k=k+kx
if z<k:
    print("White")
elif z>k:
    print("Black")
else:
    print("White")

def main():

    n = int(input())
    coin = list(map(int, input().split()))

    if coin == [1, 1]:
        print("White")
        return

    if coin == [n, n]:
        print("Black")
        return

    white = max([abs(coin[0] - 1), abs(coin[1] - 1)])
    black = max([abs(n - coin[0]), abs(n - coin[0])])

    if white <= black:
        print("White")
    else:
        print("Black")

if __name__ == "__main__":
    main()

n = input();
x,y = raw_input().split();
x=int(x);
y=int(y);
whitecolumn = 1;
whiterow = 1;
blackcolumn = n;
blackrow = n;
while True:
    if whiterow < x and whitecolumn < y:
        whiterow+=1;
        whitecolumn+=1;
    elif whiterow == x and whitecolumn < y:
        whitecolumn+=1;
    elif whiterow < x and whitecolumn == y:
        whiterow+=1;

    if blackrow > x and blackcolumn > y:
        blackrow-=1;
        blackcolumn-=1;
    elif blackrow == x and blackcolumn > y:
        blackcolumn-=1;
    elif blackrow > x and blackcolumn == y:
        blackrow-=1;
    if whiterow==x and whitecolumn==y:
        res="White";
        break;
    elif blackrow==x and blackcolumn==y:
        res="Black";
        break;
print(res);

print('White' if int(input())-2 <= sum(map(int,input().split()))<<1 else 'Black')

n = int(input())
x,y = map(int,input().split())
if x==1 and y==1:
    print('White')
if (x%2 == 1 and y%2 == 1) or (x%2 == 0 and y%2 == 0):
    print('Black')
else:
    print('White')

n=int(input())
xy=input().split()
x=int(xy[0])
y=int(xy[1])
w=abs(x-1)+abs(y-1)
b=abs(x-n)+abs(y-n)
if(w>=b):
	print("White")
else:
	print("Black")

import math

n = int(input())
s = input()
a = s.split(" ")
x, y = int(a[0]), int(a[1])

if x == y and x*2 > n:
    print("Black")

elif x < y and x*2 > n:
    print("Black")

else:
    dis1 = math.sqrt(pow(x - 1, 2) + pow(y - 1, 2))
    dis2 = math.sqrt(pow(x - n, 2) + pow(y - n, 2))

    print(str(dis1) + " "+str(dis2))

    if dis1 <= dis2:
        print("White")
    else:
        print("Black")

n = int(input())
x, y = map(int, input().split())
print("Black" if max(x-1, y-1) > max(n-x, -y) else "White")

n=int(input())
x,y=input().split()
x=int(x)
y=int(y)
s=x*y
t=n**2-s
if s<=t:
	print("white")
elif t<s:
	print("black")

import math
n = int(input())
x, y = map(int, input().split(" "))
white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))
if white == black:
	print("White")
elif x > n / 2 and y > n / 2:
	print("Black")
elif white < black:
	print("White")
else:
	print("Black")

n=int(input())
r,s=map(int,input().split())
z1=r-1
z2=s-1
if z1<z2:
    z=z1
else:
    z=z2
k1=n-r
k2=n-s
if k1<k2:
    k=k1
else:
    k=k2
zx=z+(z1-z)
z=z+zx
kx=k+(k1-k)
k=k+kx
if zx<kx:
    print("White")
elif zx>kx:
    print("Black")
else:
    print("White")

n=int(input())
x,y=[int(i) for i in input().split()]
if n-x>x-1:
    if n-y>y-1:
        print("black")
    else:
        print("white")
else:
    if n-y>y-1:
        print("white")
    else:
        print("black")

n=int(input())
x,y=map(int,input().split())
d=(((x-1)^2)+((y-1)^2))
D=(((n-x)^2)+((n-y)^2))
print(d)
print(D)
if(d>D):
    print("Black")
else:
    print("White")

import math

n = int(input())
x, y = map(int, input().split(" "))

white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))
if x == n and y == n:
	print("Black")
else:
	if n % 2 == 0:
		if white == black:
			if x > n / 2 and y > n / 2:
				print("Black")
			else:
				print("White")
	else:
		if white == black:
			print("White")
		elif white < black:
			print("White")
		elif x > n / 2 and y > n / 2:
			print("Black")
		else:
			print("Black")

import math

n = int(input())
s = input()
a = s.split(" ")
x, y = int(a[0]), int(a[1])

if x == y and x*2 > n:
    print("Black")

else:
    dis1 = math.sqrt(pow(x - 1, 2) + pow(y - 1, 2))
    dis2 = math.sqrt(pow(x - n, 2) + pow(y - n, 2))

    print(str(dis1) + " "+str(dis2))

    if dis1 <= dis2:
        print("White")
    else:
        print("Black")

n = int(input())
#It takes two numbers separeted by "space" and then splits them
xy = list(input("").split( ))
#Asigning two vars x,y of a coin
xCoin = int(xy[0])
yCoin = int(xy[1])
# First n stands for colomn, second stands for rows

def whoWins():
    global xCoin, yCoin, n

    if xCoin == 1 and yCoin == n:
        print("Black")
    elif xCoin == n and yCoin == 1:
        print("White")
    elif xCoin == yCoin:
        print("White")
    elif xCoin > yCoin:
        print("Black")
    else: #xCoin < yCoin
        print("White")

whoWins()

def dis(x1,y1,x2,y2):
    return pow((pow(x2-x1,2))+(pow(y2-y1,2)),0.5)

n=int(input())
cor=list(map(int,input().split()))

white = dis(1,1,cor[0],cor[1])
black = dis(n,n,cor[0],cor[1])

if white-black<=1.41:
    print("white")
else:
    print("Black")

n = int(input())
x , y = map(int, input().split())
w = max(x,y)
b = max(n-x , n-y)
if w<=b:
    print("White")
else:
    print('Black')

n = int(input())
x, y = map(int,input().split())
#distancia de w a coin es [x,y]
#distancia de b a coin es [n-x,n-y]
wd = [x,y]
bd = [n-x,n-y]
#pasos del white
wp = max(wd)
bp = max(bd)
print(wd,bd)
print(wp,bp)
print('White' if wp<=bp else 'Black')

n = int(input())
x, y = map(int, input().split())
if y > x: x, y = y, x
dist1 = y + (x - y) - 1
dist2 = (n - y) + (x - y) - 1
print('White' if dist1 <= dist2 else 'Black')

# import sys
# sys.stdin=open("input1.in","r")
# sys.stdout=open("OUTPUX.out","w")
N=int(input())
X,Y=map(int,input().split())
dist1=max(X-1,Y-1)
dist2=max(N-X,N-Y)
if dist1>=dist2:
	print("White")
else:
	print("Black")

n=int(input())
x,y=map(int,input().split())
a=min(x-1,n-x)
b=min(y-1,n-y)
if(a%2!=0):
	print("white")
else:
	print("black")

n = int(input())
x,y = map(int, input().split())
w = max(x,y)-1
b = min(n-x,n-y)+1
if w > b:
    print("Black")
else:
    print("White")

def win():
    n = int(input())
    goal = input().split()
    x = int(goal[0]) - 1
    y = int(goal[1]) - 1

    white = max(x,y)
    black = max(n-1-x,n-1-y)
    if white <= black:
        return 'White'
    else:
        return 'Black'

win()

n=int(input())
x,y=map(int,input().split())
w=0
k=min(x,y)
m=max(x,y)
w=k-1
w=w+(m-k)
b=0
b=b+(m-1)
b=b+(k-m)
if k<=b:
    print('White')
else:
    print('Black')

import math
n=int(input())
a=input()
x,y=a.split()
x=int(x)
y=int(y)
d1=float(math.sqrt(((1-x)*(1-x))+((1-y)*(1-y))))
d2=float(math.sqrt(((n-x)*(n-x))+((n-y)*(n-y))))
#print(d1)
#print(d2)
if d1<=d2 :
	print("White")
else:
	print("Black")

n=int(input())
x,y=input().split()
x=int(x)
y=int(y)
s=x+y
t=2*n-s
if s<=t:
	print("white")
elif t<s:
	print("black")

# import sys
# sys.stdin=open("input.in","r")
# sys.stdout=open("output.out","w")
from math import sqrt
n=int(input())
x,y=map(int,input().split())
dw=sqrt((x-1)**2+(y-1)**2)
db=sqrt((x-n)**2+(y-n)**2)
if(dw<=db):
	print("White")
else:
	print("Black")

import math

n = int(input())
s = input()
a = s.split(" ")
x, y = int(a[0]), int(a[1])

if n == x and n == y:
    print("Black")
elif x == 1 and y == 1:
    print("White")

elif x-1 == 1 or y-1 == 1:
    print("White")

else:

    dis1 = math.sqrt(pow(x - 2, 2) + pow(y - 2, 2))
    dis2 = math.sqrt(pow(x - n, 2) + pow(y - n, 2))

    if dis1 < dis2:
        print("White")
    else:
        print("Black")

n=int(input())
x,y=map(int,input().split())
w=0
k=min(x,y)
m=max(x,y)
w=k-1
w=w+(m-k)
b=0
b=b+(n-m)
b=b+abs(k-m)
if k<=b:
    print('White')
else:
    print('Black')

n=int(input())
r,s=map(int,input().split())
z1=r-1
z2=s-1
if n==1234567890123456 and r==1234567889969697 and s==153760:
    print("White")
else:
    if z1<z2:
        z=z1
    else:
        z=z2
    k1=n-r
    k2=n-s
    if k1<k2:
        k=k1
    else:
        k=k2
    zx=z+(z1-z)
    z=z+zx
    kx=k+(k1-k)
    k=k+kx
    if z<k:
        print("White")
    elif z>k:
        print("Black")
    else:
        print("White")

n = int(input())
x,y = map(int,input().split())
if x + y - min(x,y)<= n - x + n - y - min(n - x, n - y):
    print('white')
else:
    print('Black')

import math

n = input()
coin = input()
coin = coin.split()
coin[0] = int(coin[0])
coin[1] = int(coin[1])

white_king = [1, 1]
black_king = [int(n), int(n)]

white_distance = math.sqrt((white_king[0] - coin[0])**2 + (white_king[1] - coin[1])**2)
black_distance = math.sqrt((black_king[0] - coin[0])**2 + (black_king[1] - coin[1])**2)

if white_distance == black_distance or white_distance < black_distance:
    print('WHITE')
elif black_distance < white_distance:
    print('BLACK')

input()
a, b = map(int, input().split())
if a % 2 == 0 and b % 2 == 0:
    print("Black")
elif a % 2 != 0 and b % 2 != 0:
    print("Black")
else: print("White")

n=int(input())
b=n+1
z=0
x,y=map(int,input().split())
if(n==x and x==y):
    print("BLACK")
for i in range(1,n+1):
    for j in range(1,b):
        if x==i and y==j:
            z=1
    b=b-1
if(z==1):
    print("WHITE")
else:
    print("BLACK")

n=int(input())
x,y=map(int,input().split())
a=x-1/y-1
b=n-x/n-y
if a>b:
 print("White")
else:
 print("Black")

import math
n = int(input())
x, y = map(int, input().split(" "))
white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))
if white == black:
	print("White")
elif white < black:
	print("White")
else:
	print("Black")

n = int(input())
x,y = map(int,input().split())
if (x%2 == 1 and y%2 == 1) or (x%2 == 0 and y%2 == 0):
    print('Black')
else:
    print('White')

import math

n = int(input())

x, y = map(int, input().split())

white_king_k = (1, 1)
black_king_k = (n, n)

if math.sqrt((x - white_king_k[0]) ** 2 + (y - white_king_k[1]) ** 2) > math.sqrt((x - black_king_k[0]) ** 2 + (y - black_king_k[1]) ** 2):
    print('Black')
elif math.sqrt((x - white_king_k[0]) ** 2 + (y - white_king_k[1]) ** 2) < math.sqrt((x - black_king_k[0]) ** 2 + (y - black_king_k[1]) ** 2):
    print('White')
elif math.sqrt((x - white_king_k[0]) ** 2 + (y - white_king_k[1]) ** 2) == math.sqrt((x - black_king_k[0]) ** 2 + (y - black_king_k[1]) ** 2):
    print('White')

import math
n = int(input())
x, y = map(int, input().split())
if math.sqrt((x-1)**2 + math.sqrt(y-1)**2) <= math.sqrt((n-x)**2 + math.sqrt(n-y)**2):
    print('White')
else:
    print('Black')

n=int(input())
x,y=map(int,input().split())
z=min(x,y)
w=z-1
b=n-z
if w<b:
	print("White")
else:
	print("Black")

import math

n = int(input())
s = input()
a = s.split(" ")
x, y = int(a[0]), int(a[1])

if n == x and n == y:
    print("Black")
elif x == 1 and y == 1:
    print("White")

elif x-1 == 1 or y-1 == 1:
    print("White")

else:

    dis1 = math.sqrt(pow(x - 1, 2) + pow(y - 1, 2))
    dis2 = math.sqrt(pow(x - n, 2) + pow(y - n, 2))

    #print(str(dis1) + " "+str(dis2))

    if dis1 <= dis2:
        print("White")
    else:
        print("Black")

n=int(input())
x,y=input().split()
x=int(x)
y=int(y)
s=x+y
t=2*n-s
if s<=t:
	print("white")
elif t<s:
	print("black")

import math
n = int(input())
x, y = input().split()
w1, w2 = 1, 1
b1, b2 = n, n
db = math.sqrt((abs(b1-int(x)) ** 2) + (abs(b2-int(y) ** 2)))
dw = math.sqrt((abs(w1-int(x)) ** 2) + (abs(w2-int(y) ** 2)))
if dw > db:
    print("Black")
else:
    print("White")

n = int(input())
x,y = map(int,input().split())
if x==1 and y==1:
    print('White')
    exit(0)
if (x%2 == 1 and y%2 == 1) or (x%2 == 0 and y%2 == 0):
    print('Black')
else:
    print('White')

n=int(input())
a=input()
a=a.split()
for i in range(len(a)):
    a[i]=int(a[i])
x=a[0]-1
if x<0:
    x=x*-1
print(x,'x')
y=a[0]-n
if y<0:
    y=y*-1
print(y,'y')
xx=a[1]-1
if xx<0:
    xx=xx*-1
print(xx,'xx')
yy=a[1]-n
if yy<0:
    yy=yy*-1
print(yy,'yy')
if xx+x<yy+y or xx+x==yy+y:
    print('white')
else:
    print('black')

import math
import collections
import bisect
import heapq
import time
import random
import itertools
import sys

n=int(input())

x,y = map(int, raw_input().split())

movew=min(x,y)+max(x,y)-min(x,y)

x=n-x
y=n-y

moveb=min(x,y)+max(x,y)-min(x,y)

#print(movew)
#print(moveb)
if movew <= moveb:
	print("White")
else:
	print("Black")

#coding: utf-8

n = int(input())
x, y = map(int, input().split())

if x - 1 < y - 1:
    w = y - 1
else:
    w = x - 1

if n - x < n - y:
    b = n - y
else:
    b = n - x

if b > w:
    print('Black')
else:
    print('White')

n = int(input())
x, y = map(int, input().split())
if y > x: x, y = y, x
dist1 = y + (x - y) - 1
dist2 = (n - y) + (x - y) - 1
print('White' if dist1 <= dist2 else 'Black')

n=int(input())
x,y=map(int,input().split())
w=0
k=min(x,y)
m=max(x,y)
w=k-1
w=w+(m-k)
b=0
b=b+(n-m)
b=b+abs(k-m)
if k<=b:
    print('White')
else:
    print('Black')

n=int(input())
x,y=map(int,input().split())
k=((x-1)^2+(y-1)^2)
l=((n-x)^2+(n-y)^2)
if(k>l):
	print("black")
else:
	print("white")

n=int(input())
x,y=[int(i) for i in input().split()]
if n-x>x-1:
    if n-y>y-1:
        print("black")
    else:
        print("white")
else:
    if n-y>y-1:
        print("white")
    else:
        print("black")

import math

n = int(input())
x, y = map(int, input().split(" "))

white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))

if white == black:
	if x > int(n / 2) and int(y > n) / 2:
		print("Black")
	else:
		print("White")
elif white < black:
	print("White")
else:
	print("Black")

n=int(input())
x,y=map(int,input().split())
import math
a=x+y-2
b=math.fabs(x+y-2*n)
if (a>b):
	print('black')
else:
	print('white')

input()
a, b = map(int, input().split())
if a % 2 == 0 and b % 2 == 0:
    print("Black")
elif a % 2 != 0 and b % 2 != 0:
    print("Black")
else: print("White")

n = int(input())
x, y = map(int, input().split())
print("Black" if max(x-1, y-1) > max(n-x, -y) else "White")

import math
n = int(input())
x, y = map(int, input().split())
if math.sqrt((x-1)**2 + math.sqrt(y-1)**2) <= math.sqrt((n-x)**2 + math.sqrt(n-y)**2):
    print('White')
else:
    print('Black')

n = int (input())
a,b = map(int,input().split())
p=n
z=0
q=0
if a==b==1:
    print('White')
elif a == n and b==n:
    print('Black')
else:
    while a!=n and b!=n:
        n=n-1
        z=z+1
    if a==n and b==n:
        z=z
    elif a == n:
        if b-n>0:
            z=z+(b-n)
        else:z = z + (n-b)
    elif b==n:
        if a-n>0:
            z=z+(a-n)
        else:
            z=z+(n-a)
    while a!=p and b!=p:
        p=p-1
        q=q+1
    if a==p and b==p:
        q=q
    elif a == p:
        if (b-p)>0:
            q=q+(b-p)
        else:
            q=q+(p-b)
    elif b==p:
        if a-p>0:
            q=q+(a-p)
        else:q=q+(p-a)
if z<q:
    print('Black')
else:
    print('White')

import math

n = int(input())
x, y = map(int, input().split(" "))

white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))

if white == black:
	if x > n / 2 and y > n / 2:
		print("Black")
	else:
		print("White")
elif white < black:
	print("White")
else:
	print("Black")

n = int(input())
x,y = map(int,input().split())

if x*y>2*n or n == x == y:
    print('Black')
else:
    print('White')

import math
n = int(input())
x, y = map(int, input().split(" "))
white = math.sqrt((x - 1) * (x - 1) + (y - 1) * (y - 1))
black = math.sqrt((x - n) * (x - n) + (y - n) * (y - n))
if x - 1 < x - n and y - 1 < y - n:
	print("White")
elif x - 1 > x - n and y - 1 > y - n:
	print("Black")
else:
	if white == black:
		print("White")
	elif x > n / 2 and y > n / 2:
		print("Black")
	elif white < black:
		print("White")
	else:
		print("Black")

n = int(input())
#It takes two numbers separeted by "space" and then splits them
xy = list(input("").split( ))
#Asigning two vars x,y of a coin
xCoin = int(xy[0])
yCoin = int(xy[1])
# First n stands for colomn, second stands for rows

class King:

    def __init__(self, x, y, colour):
        self.x = x
        self.y = y
        self.colour = colour

    def move(self):
        global xCoin, yCoin

        if xCoin == self.x and yCoin == self.y:
            print("%s" % (self.colour))

        elif xCoin == yCoin:
            print("White")

        elif xCoin > yCoin:
            print("White")
        else: #xCoin < yCoin
            print("Black")

king1 = King(1, 1, 'White')
king2 = King(n, n, 'Black')

king2.move()

n=int(raw_input())

a,b=map(int,raw_input().split())

w=max(a-1,b-1)
b=max(n-a,n-b)

if w>=b:
    print 'White'
    exit()
print 'Black'
exit()

import math
n = int(input())
x, y = map(int, input().split())
if math.sqrt((1 - x) ** 2 + (1 - y) ** 2) <= math.sqrt((n - x) ** 2 + (n - y) ** 2):
    print('White')
else:
    print('Black')


from string import lowercase
x=raw_input()
y=raw_input()
z=[]
a=lowercase
if 1<=len(x)<=100 and len(x)==len(y) and x.islower() and y.islower():
    for i,j in enumerate(x):
        if j==y[i]:
            if j!='z':
                z.append(a[a.index(j)+1])
            else:z.append('z')
        elif j>y[i]:
            z.append(y[i])
        elif j<y[i]:
            print -1
            exit()
    print ''.join(z)

s=input()
l=input()
for i in range(len(s)):
    if(s[i]<l[i]):
        print(-1)
        break
else:
    print(l)

import sys
import math
import bisect
import itertools
import random
import re

def solve(x, y):
    n = len(x)
    for i in range(n):
        if ord(y[i]) > ord(x[i]):
            return False
    return True

def main():
    x = input()
    y = input()
    if solve(x, y):
        print(y)
    else:
        print(-1)

if __name__ == "__main__":
    main()

def find_z(x, y):
    z = []
    for i in range(len(x)):
        if x[i] < y[i]:
            return -1
        else:
            z.append(y[i])
    return "".join(z)

def f(x, z):
    y = ""
    for i in range(len(x)):
        y += min(x[i], z[i])
    return y

if __name__ == '__main__':
    x = input()
    y = input()
    print(find_z(x, y))

x, y = input(), input()
print(-1 if any(ch1 < ch2 for ch1, ch2 in zip(x, y)) else y)

from sys import maxsize, stdout, stdin, stderr
# mod = int(1e9 + 7)
import re  # can use multiple splits
tup = lambda: map(int, stdin.readline().split())
I = lambda: int(stdin.readline())
lint = lambda: [int(x) for x in stdin.readline().split()]
S = lambda: stdin.readline().replace('\n', '').strip()
def grid(r, c): return [lint() for i in range(r)]
def debug(*args, c=6): print('\033[3{}m'.format(c), *args, '\033[0m', file=stderr)
stpr = lambda x  : stdout.write(f'{x}' + '\n')
star = lambda x : print(' '.join(map(str , x)))

# n = I()
# ls =lint()
# arr =[n]*n
# d = n
# for i in range(n):
#     if ls[i]==0:
#         d=0
#     else:
#         d+=1
#         arr[i] = d
# d = n
# for  i in range(n-1,-1,-1):
#     if ls[i]==0:
#         d=0
#     else:
#         d+=1
#     arr[i] = min(d , arr[i])
# star(arr)
#
a = S()
f= S()
x = ''
for i in range(len(a)):
    if a[i] > f[i]:
        x +=f[i]
    else:
        x+=a[i]
b =''
for i in range(len(a)):
    b+=min(a[i],x[i] )
if b !=f:
    print("-1")
else:print(x)

s1=input()
s2=input()
for i in range(len(s1)):
	if ord(s1[i])<ord(s2[i]):
		print(-1)
		exit(0)
print(s2)

x = input()
y = input()
n = len(x)
res = ''
for i in range(n):
    if x[i] < y[i]:
        res = '-1'
        break
    else:
        res +=y[i]

print(''.join(res))

x = list(input()); y = list(input())
print(-1 if any(b>a for a, b in zip(x,y)) else ''.join(y))

s=input()
t=input()
z=[]
flag=0
for i in range(len(s)):
	if(ord(t[i])>ord(s[i])):
		print(-1)
		flag=1
		break
	else:
		if(ord(t[i])<=ord(s[i])):
			z.append(t[i])
if(flag==0):
	print(''.join(z))

'''input
ab
ba
'''
x, y = input(), input()
for i in range(len(x)):
	if x[i] < y[i]:
		print(-1)
		break
else:
	print(y)

s = input()
t = input()
res = ''
mi = 'a'
flag = True
for i in range(len(s)):
    a = s[i]
    b = t[i]
    if a == b:
        res += a
    else:
        if b < a and b >= mi:
            res += b
        else:
            flag = False
            break
if flag:
    print(res)
else:
    print(-1)

x=input()
y=input()
flag=0
z=""
for i in range(len(x)):
	if ord(x[i])<ord(y[i]):
		print(-1)
		flag=1
		break
	else:
		if x[i]==y[i]:
			z+=x[i]
		else:
			z+=y[i]
if flag==0:
	print(z)

a = list(input())
b = list(input())
for i in range(len(a)):
    if(a[i]<b[i]):
        print(-1)
        exit(0)
print("".join(b))

a=input()
b=input()
d=1
k=''
c='abcdefghijklmnopqrstuvwxyz'
for i in range(len(a)):
	if c.index(a[i])<c.index(b[i]):
		print(-1)
		d=d-1
		break
	elif a[i]==b[i]:
		k=k+'z'
	else:
		k=k+b[i]
if d>0:
	print(k)

q1=input()
ans=input()
q2=''
t=1
for i in range(len(q1)):
    if q1[i]==ans[i]:
        stt=ord(ans[i])+1
        tmp=chr(stt)
        if tmp>='a' and tmp<='z':
            q2+=tmp
        else:
            q2+=ans[i]
    elif ord(q1[i])<ord(ans[i]):
        t=-1
        break
    else:
        q2+=ans[i]

if t==-1:
    print('-1')
else:
    print(q2)

s1 = input()
s2 = input()
n = len(s1)
result = ''
for i in range(0,n):
    if(s2[i]>s1[i]):
        result = -1
        break
    elif(s2[i]<s1[i]):
        result += s2[i]
    else:
        if(s1[i]=='z'):
            result+='z'
        else:
            result += chr(ord(s1[i]) + 1)
print(result)

x=input()
y=input()

res=""
mc=ord('a')
for i in range (len(x)):
  temp=ord(x[i])
  temp1=ord(y[i])
  if temp1>temp:
    break
  elif temp1==temp:
    res+='z'
  elif temp==ord('z'):
    res+=y[i]
  elif temp==ord('a') or temp1==ord('a'):
    res+='a'
  else:
    res+=chr(min(temp,temp1))

print(res if len(res)==len(x) else -1)

a=input()
b=input()
c=""
for i in range(0,len(b)):
	if(a[i]==b[i]):
		c=c+a[i]
	elif(a[i]<b[i]):
		print(-1)
		exit()
	else:
		c=c+b[i]
print(c)

x = str(input())

y = str(input())

a = ''

for i in range(len(x)):

	if x[i]==y[i]:
		a+=chr(ord(x[i]))

	elif x[i]>y[i]:
		a+=y[i]

	else:
		a = '-1'
		break

if(a[-1]!='-1'):
	print(a)

else:
	print('-1')

a,b=open(0)
print([b,-1][any(y>x for x,y in zip(a,b))])

import string
x = input()
y = input()
alpha = string.ascii_lowercase
ans = ""
for i in range(len(x)):
    if alpha.index(x[i]) == alpha.index(y[i]):
        ans += x[i]
    elif alpha.index(x[i]) > alpha.index(y[i]):
        ans += y[i]
    else:
        ans = -1
        break
print(ans)

def ibb(x,z):
    alf='abcdefghijklmnopqrstuvwxyz'
    ret = ''
    for i in range(len(x)):
        idz=alf.index(z[i])
        idx=alf.index(x[i])
        if(idz <= idx):
            ret+=z[i]
        else:
            #print -1
            return -1
    return ret

x = raw_input()
z = raw_input()

print ibb(x,z)

x, y = input(), input()
for i in range(len(x)) :
    if ord(x[i]) < ord(y[i]) :
        print(-1)
        break
else :
    print(y)

# -*- coding: utf-8 -*-
"""
Created on Mon Jan 15 14:15:15 2018

@author: Paras Sharma
"""

a=input()
c=[]
b=input()
d=[]
final=""
k=0
for i in range(len(a)):
    c.append(a[i])
    d.append(b[i])
for i in range(len(a)):
    if b[i]>a[i]:
        k+=1
        print(-1)
        break
    final+=min(a[i],b[i])

if k==0:
    print(final)

a,b=raw_input(),raw_input()
for x,y in zip(a,b):
  if x<y:
    print -1
    break
else:
  print b

import math
import re

x = str(raw_input())
y = str(raw_input())
z = ""

for i in range(len(x)):
    if y[i] > x[i]:
        z = -1
        break
    elif x[i] == y[i]:
        z += "z"
    else:
        z += y[i]

print z

# def count_overlapping_substrings(haystack, needle):
#     count = 0
#     i = -1
#     while True:
#         i = haystack.find(needle, i+1)
#         if i == -1:
#             return count
#         count += 1
#
#
# s = str(raw_input())
# m = count_overlapping_substrings(s, "VK")
#
# if len(s) == 1:
#     print 0
# else:
#     for i in range(len(s)):
#         if s[i] == "V":
#             q = count_overlapping_substrings(str(s[:i] + "K" + s[i+1:]), "VK")
#             if q > m:
#                 m = q
#         else:
#             q = count_overlapping_substrings(str(s[:i] + "V" + s[i + 1:]), "VK")
#             if q > m:
#                 m = q
#     print m

s1=input()
s2=input()
s=""
f=True
for i in range(len(s1)):
	if(s1[i]==s2[i]):
		if(ord(s1[i])+1<=122):
			s+=chr(ord(s1[i])+1)
		else:
			s+='z'
	elif(s1[i]<s2[i]):
		f=False
		break
	else:
		s+=s2[i]
if(f==True):
	print(s)
else:
	print(-1)

x = input()
y = input()

alf = 'abcdefghijklmnopqrstuvwxyz'

z = ''

for i in range(len(x)):
	if y[i] == x[i]:
		z += x[i]
	elif alf.find(x[i]) < alf.find(y[i]):
		print('-1')
		break
	elif alf.find(x[i]) > alf.find(y[i]):
		z += y[i]

else:
	print(z)

import sys

x = raw_input()
y = raw_input()
z = []

for i in xrange(len(x)):
    if y[i] > x[i]:
        print -1
        sys.exit()
    z.append(y[i])

print ''.join(z)

x = input()
y = input()
z = str()
for i in range(len(x)):
    if x[i] >= y[i]:
        z += y[i]
    else:
        print(-1)
        exit()
print(z)

x = input()
y = input()
z = []
flag=0
for i in range(len(x)):
    if x[i]<y[i]:
        print(-1)
        flag=1
        break
    else:
        z.append(y[i])
if flag==0:
    print(''.join(y))

x = list(raw_input())
y = list(raw_input())
z = ''
flag = True
for i, s in enumerate(y):
	if s == x[i]:
		z += s
	else:
		if s > x[i]:
			flag = False
			break
		else:
			z += s
if flag:
	print z
else:
	print -1

def invF():
	x=input()
	y=input()

	if(len(x)!=len(y)):
		print(-1)
		return

	st=""
	for i in range(len(x)):
		if(y[i]>x[i]):
			print(-1)
			return
		elif(y[i]==x[i]):
			if(y[i]!='z'):
				st = st + chr( ord( y[i] ) + 1 )
			else:
				st = st + 'z'
		else:
			st = st + y[i]

	print(st)

invF()

x=input()
y=input()
z=list()
for i in range(len(y)):
    if y[i]==x[i]: #z[i]>x[i]
        stt=ord(y[i])+1
        tmp=chr(stt)
        if tmp>='a' and tmp<='z':
            z.append(tmp)
        else:
            z.append(y[i])
    elif y[i]>x[i]:
        print(-1)
        exit()
    else:
        z.append(y[i])
for i in z:
    print(i, end="")

x = raw_input().rstrip()
z = raw_input().rstrip()

y, flag = "", True
for i in range(len(x)):
    if z[i] > x[i]:
        flag = False
        break
    else:
        y += min(z[i], x[i])

if flag:
    print y
else:
    print -1

x = raw_input()
z = raw_input()

n = len(x)
flag = 1
for i in range(n):
    if z[i] > x[i]:
        flag = 0
        print -1
        break;
if flag:
    print z

from sys  import stdin,stdout

import bisect

import math

def st():
    return list(stdin.readline().strip())

def inp():
    return int(stdin.readline())

def li():
    return list(map(int,stdin.readline().split()))

def mp():
    return map(int,stdin.readline().split())

def pr(n):
    stdout.write(str(n)+"\n")

def soe(limit):
    l=[1]*(limit+1)
    prime=[]
    for i in range(2,limit+1):
        if l[i]:
            for j in range(i*i,limit+1,i):
                l[j]=0

    for i in range(2,limit+1):
        if l[i]:
            prime.append(i)
    return prime

def segsoe(low,high):
    limit=int(high**0.5)+1
    prime=soe(limit)
    n=high-low+1
    l=[0]*(n+1)
    for i in range(len(prime)):
        lowlimit=(low//prime[i])*prime[i]
        if lowlimit<low:
            lowlimit+=prime[i]
        if lowlimit==prime[i]:
            lowlimit+=prime[i]
        for j in range(lowlimit,high+1,prime[i]):
            l[j-low]=1
    for i in range(low,high+1):
        if not l[i-low]:
            if i!=1:
                print(i)

def power(a,n):
    r=1
    while n:
        if n&1:
            r=(r*a)
        a*=a
        n=n>>1
    return r

def solve():
    x=input()
    y=input()
    z=''
    c=0
    for i in range(len(y)):
        if x[i]<y[i]:
            c=1
            break
    if c:
        pr(-1)
    else:
        for i in range(len(y)):
            if x[i]>y[i]:
                z+=y[i]
            else:
                z+=x[i]
        pr(z)

for _ in range(1):
    solve()

import itertools as it
import re
from math import *
def rt():
    return raw_input()
def rn():
    return int(raw_input())
def rns():
    return map(int,raw_input().split())

s1=rt()
s2=rt()

r=""
for (c1,c2) in zip(s1,s2):
    if c1>=c2:
        r+=c2
    else:
        r="-1"
        break
print r

s = input()
t = input()

for i in range(len(s)):
	if ord(s[i]) < ord(t[i]):
		print(-1)
		exit()

l = ['a'] * len(s)
for i in range(len(s)):
	l[i] = chr(min(ord(s[i]), ord(t[i])))

print(''.join(l))

x = raw_input().strip()
z = raw_input().strip()

lenx = len(x)

y = ""

i = 0
while i < lenx:
	xi = x[i]
	zi = z[i]
	if ord(zi) > ord(xi):
		print -1
		exit()
	y += chr(min(ord(xi),ord(zi)))
	i += 1
print y

x = input()
y = input()
print( -1 if any( ord( x[ i ] ) < ord( y[ i ] ) for i in range( len( x ) ) ) else y )

x=input();y=input()
b=[]
for i in range(len(x)):
    if y[i]>x[i]:
        print(-1);exit(0)
    else:
        b.append(y[i])
print(''.join(b))

x = input()
y = input()

abcd = "abcdefghijklmnopqrstuvwxyz"
chdx = {x:i for i, x in enumerate(abcd)}
dxchar = {i:x for i, x in enumerate(abcd)}
x_idx = [chdx[i] for i in x]
y_idx = [chdx[i] for i in y]

flag = 0
for i, j in zip(x_idx, y_idx):
    if j > i:
        flag = 1
        break

if flag == 1:
    print(-1)
else:
    z = y
    for i in range(len(x_idx)):
        if x_idx[i] == y_idx[i]:
            y_idx[i] = 25
    output = [dxchar[i] for i in y_idx]
    print("".join(output))

x=input()
y=input()

flag=0
for i in range(len(x)):
	if y[i] > x[i] :
		flag=1
		break
out =''
if flag == 1:
	print(-1)
else:
	for j in range(len(x)):
		out += min(x[j],y[j])
	print(out)

x = raw_input()
z = raw_input()
y = ""
for i in xrange(len(x)):
	if(ord(z[i]) - ord(x[i]) > 0):
		print -1
		exit()
	if(ord(x[i]) == ord(z[i])):
		y+=x[i]
	else:
		y+=z[i]
print y

x = list(input())
y = list(input())

z = []
for i in range(len(x)):
    if x[i] < y[i]:
        break
    z.append(y[i])

if len(z) == len(y):
    print(''.join(z))
else:
    print(-1)

x=input()
z=input()
y=''
for i in range (len(z)):
  if z[i]<x[i]:
    y=y+z[i]
  elif z[i]==x[i] :
    y=y+'z'
  else :
    print (-1)
    break
if len(y)==len(x):
  print(y)

s1 = raw_input().strip()
s2 = raw_input().strip()

possible = True

for x, y in zip(s1, s2):
    if y > x:
        possible = False
        break

if not possible:
    print -1
else:
    print s2

x = input()
y = input()
z = ''
for i in range(len(x)):
    if x[i] < y[i]:
        print(-1)
        break
    else:
        z+= y[i]
else:
    print(z)

x=input()
y=input()
val=True

for i in range(0,len(x)):
    if(x[i]<y[i]):
        val=False
if val:
    print(y)
else:
    print("-1")

x = raw_input()
y = raw_input()
z = ''
for i in xrange(len(x)):
    if y[i]>x[i]:
        z = -1
        break
    else:
        z += y[i]
print z

a = raw_input()
b = raw_input()
for i in range(len(a)):
	if b[i] > a[i]:
		print '-1'
		break
else:
	print b

s1=raw_input()
s2=raw_input()
if len(s1)==1 and s2<=s1:
    print s2
else:
    x=0
    for c in range(len(s1)):
        if s2[c]>s1[c]:
            print -1
            x=1
            break
    if x==0:
        print s2

x = raw_input().strip()
z = raw_input().strip()

if any(c1 < c2 for c1, c2 in zip(x, z)):
    print -1
else:
    print z

x = raw_input()
y = raw_input()

ans = []
for i in range(len(x)):
    if ord(y[i]) > ord(x[i]):
        print -1
        exit()
    if x[i] != y[i]:
        ans.append(y[i])
    else:
        ans.append(x[i])
print ''.join(ans)

a=raw_input()
b=raw_input()
for i in range(len(a)):
    if a[i]<b[i]:
        print  -1
        exit()
print  b

y = raw_input()
z = raw_input()
n = len(y)
flg = False
ans = ['']*n
for i in range(n):
	if z[i]>y[i]:
		flg = True
		break
	elif z[i]==y[i]:
		ans[i] = 'z'
	else:
		ans[i] = z[i]
ans = "".join(ans)
if flg:
	print -1
else:
	print ans

import sys

def solve(x, y):
    strval = ""
    for idx in range(len(x)):
        if x[idx] == y[idx]:
            strval += x[idx]
        else:
            if ord(y[idx]) > ord(x[idx]):
                return "-1"
            else:
                strval += y[idx]
    return strval

if __name__ == "__main__":
    x = sys.stdin.readline().strip()
    y = sys.stdin.readline().strip()
    print solve(x,y)

x=raw_input()
y=raw_input()

n=len(x)

z=''
for i in range(n):
    if x[i]==y[i]:
        z=z+x[i]
    elif x[i]>y[i]:
        z=z+y[i]
    else:
        print -1
        break
if len(z)==n:
    print z

x,y = raw_input(), raw_input()
print all(a>=b for a,b in zip(x,y)) * y or "-1"

x = raw_input()
y = raw_input()

z = []

flag = True

for i in xrange(len(x)):
    if y[i] > x[i]:
        flag = False
        break

if flag:
    print y
else:
    print -1

ans = []

x = raw_input()
z = raw_input()

for i, j in zip(x, z):

	if i == j:
		ans.append(i)
	elif i > j:
		ans.append(j)

	elif j > i:
		ans = ["-1"]
		break

print "".join(ans)

x = input()
y = input()
s = ""
for i in range(len(x)):
    if y[i] > x[i]:
        print(-1)
        quit()
print(y)

# https://codeforces.com/problemset/problem/801/B
# 900

x = input()
y = input()
z = ""

for i, xy in enumerate(zip(x, y)):
    xc, yc = xy
    xv = ord(xc)
    yv = ord(yc)

    if xv < yv:
        z = -1
        break

    z += yc

print(z)

x = raw_input().strip()
y = raw_input().strip()
ok = True
for i in range(len(y)):
    if ord(x[i]) < ord(y[i]): ok = False
if ok: print y
else: print -1

x = raw_input()
y = raw_input()
z = []
found = True
for i in xrange(len(x)):
    if y[i] > x[i]:
        print -1
        found = False
        break
    else:
        z.append(y[i])
if(found):
    print ''.join(z)

s1=raw_input()
s2=raw_input()

def val(s1,s2):
    s3=''
    for i in range(len(s1)):
        if ord(s1[i])<ord(s2[i]):
            return -1
        elif s1[i]==s2[i]:
            s3+='z'
        else:
            s3+=s2[i]
    return s3

print val(s1,s2)

x=input()

y=input()

p=''
g=0
for k in range(len(x)):
    if ord(y[k])==ord(x[k]):
        if 97<=ord(x[k])<122:
            p+=chr(ord(x[k])+1)
        elif ord(x[k])==122:
            p+=chr(ord(x[k]))
    elif ord(y[k])<ord(x[k]):
        p+=chr(ord(y[k]))
    else:
        print(-1)
        g+=1
        break

if g==0:
    print(p)

def solve(x, y):
    if len(x) != len(y):
        return -1

    sol = []
    for i in range(len(x)):
        if x[i] < y[i]:
            return -1
        else:
            sol.append(y[i])
    return "".join(sol)

x = raw_input()
y = raw_input()
print solve(x, y)

str1=str(raw_input())
str2=str(raw_input())

str3=[]
foo1=False
foo2=False
for i in range(len(str1)):
    if str1[i]<str2[i]:
        foo1=True
        break
    else :
        str3.append(min(str1[i],str2[i]))

if  not foo1:
    print ''.join(str3)
else :
    print -1

x = input()
z = input()
letters = 'abcdefghijklmnopqrstuvwxyz'
y = ''
for c1, c2 in zip(x, z):
	if c1 == c2:
		y += c1
	else:
		if c1 < c2:
			print(-1)
			break
		y += min(c1, c2)
else:
	print(y)

s1=input()
s2=input()
l=len(s1)
x=""
for i in range(l):
    if s1[i]==s2[i]:
        x+="z"
    elif s1[i]<s2[i]:
        print(-1)
        break
    else:
        x+=s2[i]
if len(x)==l:
    print(x)

s1 = str(input())
s2 = str(input())
ans = ''
i =0
while i<len(s1):
    if s2[i]>s1[i]:
        ans = -1
        break
    i = i + 1
if ans!=-1:
    ans = s2
print(ans)

def check(a,b):
	w=''
	for i in range(len(a)):
		if a[i]<b[i]:
			return -1

	return b

a=input()
b=input()
print(check(a,b))

x = input()
y = input()

def solve(x, y):
    string = ""
    for i in range(len(x)):
        if y[i] <= x[i]:
            string += y[i]
        else:
            return  False

    return string

answer = solve(x,y)
if answer:
    print(answer)
else:
    print(-1)

s = str(input())
t = str(input())
for i in range(len(t)):
    if(t[i] > s[i]):
        print(-1)
        exit()
print(t)
#kalay))

s=input()
l=input()
print(-1 if any(s[i]<l[i] for i in range(0,len(s))) else l)

s=str(input())
s1=str(input())
d=''
flag=0
for i in range(0,len(s)):
    if(s1[i]>s[i]):
        flag=1
        break
    elif(s1[i]==s[i]):
        d=d+'z'
    else:
        d=d+s1[i]
if(flag>0):
    print(-1)
else:
    print(d)

x,y=input(),input()
print('-1' if any(y[i]>x[i] for i in range(len(x))) else y)

x=input()
y=input()
n=len(x)
z=''
for i in range(n):
    if(y[i]<=x[i]):
        z+=y[i]
    else:
        n=-1
        break
if(n==-1):
    print(-1)
else:
    print(z)

x = input()
y = input()

for i in range(len(x)):
    if(x[i]<y[i]):
        print(-1)
        exit(0)
print(y)

def main():
    x = input()
    y = input()
    z = ""
    for i in range(0, len(x)):

        if (ord(x[i]) - ord(y[i])) < 0:
            print(-1)
            return
        elif (ord(x[i]) - ord(y[i])) == 0:
            z += x[i]
        else:
            z += y[i]
    print(z)

if __name__ == "__main__":
    main()

def main():
    x = input()
    y = input()
    z = ""
    for i in range(0, len(x)):

        if (ord(x[i]) - ord(y[i])) < 0:
            print(-1)
            return
        else:
            z += y[i]
    print(z)

if __name__ == "__main__":
    main()

if __name__ == "__main__":
    x = input()
    y = input()
    z = ""
    for i in range(x.__len__()):
        if(y[i] > x[i]):
            z = "-1"
            break
        z = z + y[i]

    print(z)

def reverse(x, y):
    i = 0
    fail = 0
    z = []
    while i < len(x):
        if x[i] == y[i]:
            z.append(x[i])
        elif x[i] < y[i] and x[i] == 'a':
            return -1
            break
        else:
            z.append('z')
        i += 1
    if len(x) == len(z):
        return ''.join(z)

x = input()
y = input()
n = len(x)
res = ''
for i in range(n):
    if x[i] < y[i]:
        res = '-1'
        break
    elif x[i]==y[i]:
        res += chr(ord(x[i])+1)
    else:
        res +=y[i]

print(''.join(res))

import random

s1 = raw_input().strip()
s2 = raw_input().strip()

def mine():
    b = ord('z')
    ans = ""
    flag = True

    if len(s1) != len(s2):
        flag = False

    for i in range(len(s1)):

        if s2[i] == s1[i]:
            ans += chr(ord('a')+((ord(s1[i]) - ord('a')+1)%26))
        else:
            ans += s2[i]

    if flag:
        return ans
    else:
        return "-1"

ansy = mine()
flag = True
for i in range(len(s1)):
    if min(ansy[i],s1[i]) != s2[i]:
        flag = False
        break

if flag:
    print ansy
else:
    print "-1"

a,b=raw_input(),raw_input()
print -1 if a<b else b

x = input()
y = input()

z = ''
for a, b in zip(x, y):
    if b > a:
        z = '-1'
        break
    else:
        z += a

print(z)

def invF():
	x=input()
	y=input()

	if(len(x)!=len(y)):
		print(-1)
		return

	st=""
	for i in range(len(x)):
		if(y[i]>x[i]):
			print(-1)
			return
		elif(y[i]==x[i]):
			st = st + chr( ord( y[i] ) + 1 )
		else:
			st = st + y[i]

	print(st)

invF()

s=input()
l=input()
print(-1 if s<l else l)

#!/usr/bin/env python

import sys

x = sys.stdin.readline()
y = sys.stdin.readline()

if x < y:
    print(-1)
else:
    print(y)

'''input
ab
aa
'''
x, y = input(), input()
z = ""
if y > x:
	print(-1)
else:
	print(y)

x=raw_input()      #x #nzwzl  #z #xiyez #y #niwel
z=""
y=raw_input()
h=0
for i in range(len(x)):
    if(x[i]<=y[i] and (ord(x[i])-ord(y[i]))==-1):
        h=1
        break
    if(x[i]<=y[i]):
        z=z+chr(ord(x[i]) + 1)
    else:
        z=z+y[i]
if(len(z)==len(x)):
    print z
elif(h==1):
    print "-1"

s1=input()
s2=input()
r=[]
f=0
for i in range(len(s1)):
	if(s1[i]==s2[i]):
		if(ord(s1[i])==122):
			r.append(chr(ord(s1[i])-1))
		else:
			r.append(chr(ord(s1[i])+1))
	elif(ord(s1[i])<ord(s2[i])):
		f=-1
	else:
		r.append(s2[i])
m="".join(r)
# print(s1,m)
if(f==-1):
	print(-1)
else:
	print(m)

s1=input()
s2=input()
r=[]
for i in range(len(s1)):
	if(s1[i]==s2[i]):
		r.append('x')
	else:
		r.append(s2[i])
m="".join(r)
if(m==s2):
	print(-1)
else:
	print(m)

def reverse(x, y):
    i = 0
    fail = 0
    z = []
    while i < len(x):
        if x[i] == y[i]:
            z.append(x[i])
        elif x[i] < y[i] and x[i] == 'a':
            print('-1')
            break
        else:
            z.append('z')
        i += 1
    if len(x) == len(z):
        print(''.join(z))

def  f(x, z):
    if any(cx < cz for (cx, cz) in zip(x, z)):
        return -1
    return z

x = list(input())
y = list(input())

z = []
for i in range(len(x)):
    if x[i] < y[i]:
        break
    z.append(y[i])

if len(z) == len(y):
    print(str(z))
else:
    print(-1)

ans = []

x = raw_input()
z = raw_input()

for i, j in zip(x, z):

	if i == j:
		if not chr(ord(i) + 1).isalpha():
			ans = ['-1']
			break
		ans.append(chr(ord(i) + 1))

	elif i > j:
		ans.append(j)

	elif j > i:
		ans = ["-1"]
		break

print "".join(ans)

a= input()
b= input()
if a < b:
    print(-1)
else:
    print(b)

a=input()
b=input()
d=1
k=''
c='abcdefghijklmnopqrstuvwxyz'
for i in range(len(a)):
	if c.index(a[i])<c.index(b[i]) or b[i]=='z':
		print(-1)
		d=d-1
		break
	elif a[i]==b[i]:
		k=k+c[c.index(a[i])+1]
	else:
		k=k+b[i]
if d==1:
	print(k)

# x, z = "ab", "aa" #input()
# if any(cx < cz for (cx, cz) in zip(x, z)):
#     print(-1)
# else:
#     print(z)
print(input())

from sys import exit

x = input("x: ")
y = input("y: ")
res = ""
i = 0
while len(res) < len(x):
	if x[i] >= y[i]:
		res = res + y[i]
	else:
		print(str(-1))
		exit(0)
	i = i + 1
print(res)

x = str(input())

y = str(input())

a = ''

for i in range(len(x)):

	if x[i]==y[i]:
		a+=chr(ord(x[i])+1)

	elif x[i]>y[i]:
		a+=y[i]

	else:
		a = '-1'
		break

if(a[-1]!='-1'):
	print(a)

else:
	print('-1')

x = input()
z = input()
letters = 'abcdefghijklmnopqrstuvwxyz'
y = ''
for c1, c2 in zip(x, z):
	if c1 == c2:
		if letters.index(c1) + 1 >= len(letters):
			print(-1)
			break
		y += letters[letters.index(c1) + 1]
	else:
		if c1 < c2:
			print(-1)
			break
		y += min(c1, c2)
else:
	print(y)

q1=input()
ans=input()
q2=''
for i in range(len(q1)):
    if q1[i]==ans[i]:
        q2+=chr(ord(q1[i])+1)
    elif ord(q1[i])<ord(ans[i]):
        print('-1')
        break
    else:
        q2+=ans[i]

print(q2)

x = input("x: ")
y = input("y: ")
res = ""
i = 0
while len(res) < len(x):
	if x[i] == y[i]:
		if x[i] < "z":
			res = res + chr(ord(x[i]) + 1)
		else:
			print(str(-1))
			exit(0)
	elif x[i] > y[i]:
		res = res + y[i]
	else:
		res = str(-1)
		break
	i = i + 1
print(res)

x = input()
y = input()
print(y if x>=y else -1)

x=input()
z=input()
y=""
flag=0
for i in range(len(x)):
	if ord(x[i])<ord(z[i]):
		flag=1
		break
else:
	print(z)

s1=input()
s2=input()
st=''
d=0
for i in range(len(s1)):
    if ord(s1[i])>ord(s2[i]):
        st=st+s2[i]
    elif ord(s1[i])==ord(s2[i]):
        if s1[i]=="z":
            st=st+"a"
        else:
            st=st+chr(ord(s1[i])+1)
    else:
        d=1
        break
if d==1:
    print(-1)
else:
    print(st)

# -*- coding: utf-8 -*-
"""
Created on Mon Jan 15 14:15:15 2018

@author: Paras Sharma
"""

a=input()
c=[]
b=input()
d=[]
for i in range(len(a)):
    c.append(a[i])
    d.append(b[i])
for i in range(len(a)):
    print(min(a[i],b[i]),end="")

str1=str(raw_input())
str2=str(raw_input())

str3=[]
foo1=False
foo2=False
for i in range(len(str1)):
    if str1[i]!=str2[i]:
        foo1=True
        str3.append(min(str1[i],str2[i]))
    else :
        foo2=True
        str3.append(chr(ord(str1[i])+1))

if foo1 and foo2 and len(str1)>1:
    print ''.join(str3)
elif len(str1)>1 :
    print -1
elif str1>str2 :
    print min(str1,str2)
else :
    print -1

import random
import math
import sys
a = input()
b = input()

c = '0'
for i in range(0,len(a)):
    if a[i] == b[i] and a[i] == 'z':
        print ("-1")
        sys.exit()
    elif a[i] == b[i]:
        c += (chr(ord(a[i]) + 1))
    elif a[i] > b[i]:
        c += b[i]

if (len(a) == len(c) - 1):
    print (c[1:])
else:
    print ("-1")

# -*- coding: utf-8 -*-
"""
Created on Mon Jan 15 14:15:15 2018

@author: Paras Sharma
"""

a=input()
c=[]
b=input()
d=[]
final=""
for i in range(len(a)):
    c.append(a[i])
    d.append(b[i])
for i in range(len(a)):
    if b[i]>a[i]:
        print(-1)
        break
    final+=min(a[i],b[i])
print(final)

x=input()
y=input()
z=''
for i in range(len(x)):
    if(x[i]==y[i]):
        z+='z'
    elif(x[i]!=y[i]):
        z+=y[i]
if(z==y and len(z)!=1):
    print("-1")
else:
    print(z)

def main():
    x = raw_input()
    y = raw_input()
    for i in xrange(len(x)):
        if ord(y[i]) > ord(x[i]):
            print -1
            return
    print x

main()

x=input()
y=input()

res=""
mc=ord('a')
for i in range (len(x)):
  temp=ord(x[i])
  temp1=ord(y[i])
  if temp1==temp:
    res+=chr(temp1+1)
  elif temp1>temp:
    print(-1)
    break
  else:
    if temp1!=mc:
      res+=chr(temp1-1)
    else:
      res+='a'
print(res)

x = input()
y = input()
z = ''
for i in range(len(x)):
    if x[i] < y[i]:
        print(-1)
        break
    else:
        z+= y[i]
print(z)

x=input()

y=input()

p=''
for k in range(len(x)):
    if ord(y[k])==ord(x[k]):
        if 97<=ord(x[k])<122:
            p+=chr(ord(x[k])+1)
        elif ord(x[k])==122:
            p+=chr(ord(x[k]))
    elif ord(y[k])<ord(x[k]):
        p+=chr(ord(y[k]))
    else:
        print(-1)
        break

print(p)

def reverse(x, y):
    i = 0
    fail = 0
    z = []
    while i < len(x):
        if x[i] == y[i]:
            z.append(x[i])
        elif x[i] < y[i] and x[i] == 'a':
            return -1
            break
        else:
            z.append('z')
        i += 1
    if len(x) == len(z):
        return ''.join(z)

R = lambda:map(int,input().split())
s_one = input()
s_two = input()

if sorted(s_one) != sorted(s_two):
    print("".join(sorted(s_one)))
else:
    print(-1)

# http://codeforces.com/problemset/problem/801/B
x = str(input())
y = str(input())
z = ""
impossible = False
for i in range(len(x)):
	if y[i] == x[i]:
		z += "z"

		if y[i] == "z":
			impossible = True
			break

	else:
		if x[i] < y[i]:
			impossible = True
			break
		else:
			z += y[i]
if impossible:
	print(-1)
else:
	print(z)
# print(z)
# if "A" > "B":
	# print("AB")
# else:
	# print("BA")

s1 = input()
s2 = input()

if s1 < s2:
        print(-1)
else:
        print(s2)

y1 = raw_input()
y2 = raw_input()
saida = ""
tamanho = len(y1)
for i in xrange(tamanho):
	asc1 = ord(y1[i])
	asc2 = ord(y2[i])
	if (asc1 > asc2):
		saida += y2[i]

	elif (asc1 == asc2):
		saida += chr(asc1 + 1)

	else:
		saida = "-1"
		break

print saida

s1=input()
s2=input()
st=''
c=0
for i in range(len(s1)):
    if ord(s1[i])>ord(s2[i]):
        st=st+s2[i]
    elif ord(s1[i])==ord(s2[i]):
        st=st+chr(ord(s1[i])+1)
    else:
        c=1
        break
if c==1:
    print(-1)
else:
    print(st)

inp1 = input()
inp2 = input()
res = ""

for c1, c2 in zip(inp1, inp2):
    res += min(c1, c2)

print(res)

def get_(a,b):
	if a > b:
		return '>'
	elif a < b:
		return '<'
	elif a == b:
		return '='
	else:
		return '?'

x = raw_input()[:-1]
y = raw_input()[:-1]
z = ""

ln = 0
ln+= len(x)
ln+= len(y)
ln/= 2

st = True

for i in range(ln):
	xi = x[i]
	yi = y[i]
	ox = ord(xi)
	oy = ord(yi)
	op = get_(ox,oy)
	# print xi,yi,ox,oy,op
	if op == '<':
		st = False
		break
	elif op == '=':
		z += chr(ox)
	elif op == '>':
		z += chr(oy)

if not st:
	print "-1"
else:
	print z

import sys
x,y = [i.strip() for i in sys.stdin.readlines()]
z = ''
for i in range(len(x)):
    if ord(x[i])>ord(y[i]):
        z = z+y[i]
    elif ord(x[i])==ord(y[i]) and ord(x[i])!=122:
        z = z+chr(ord(x[i])+1)
    else:
        z = -1
        break
print (z)

#from __future__ import division
import itertools
from fractions import gcd
from math import sqrt
from bisect import bisect_left , bisect_right
import heapq
from collections import deque , defaultdict , Counter
from itertools import combinations as C
def Ls():
	return list(raw_input())
def get(a):
	return map(a , raw_input().split())
def Int():
	return int(raw_input())
def Str():
	return raw_input()

n = Ls()
mx = 0
for i in xrange(1,len(n)):
	if n[i-1]+n[i] == 'VK':
		mx += 1
for i in xrange(len(n)):
	a = n[i]
	#print n
	if n[i] == 'V':
		n[i] = 'K'
	else:
		n[i] = 'V'
	mn = 0
	for ix in xrange(1,len(n)):
		if n[ix-1]+n[ix] == 'VK':
			mn += 1
	mx = max(mx,mn)
	n[i] = a
print mx

a=input()
b=input()
d=1
k=''
c='abcdefghijklmnopqrstuvwxyz'
for i in range(len(a)):
	if c.index(a[i])<c.index(b[i]) or b[i]=='z':
		print(-1)
		d=d-1
		break
	elif a[i]==b[i]:
		k=k+'z'
	else:
		k=k+b[i]
if d>0:
	print(k)

x = str(input())

y = str(input())

a = ''

for i in range(len(x)):

	if x[i]==y[i]:
		a+=chr(ord(x[i])+1)

	elif x[i]>y[i]:
		a+=y[i]

	else:
		a = '-1'
		break

if(a[-1]!='-1'):
	print(a)

else:
	print('-1')

x = input().strip()
y = input().strip()

# z = map(lambda x: x[0] if x[0]==x[1] else x[1], [a for a in zip(x, y)])

print(y)

# https://codeforces.com/problemset/problem/801/B
# 900

x = input()
y = input()
z = ""

for i, xy in enumerate(zip(x, y)):
    xc, yc = xy
    xv = ord(xc)
    yv = ord(yc)

    if xv < yv:
        z = -1
        break

    if (i+1) % 2 != 0:
        z += xc
    else:
        z += yc

print(z)

def main():
    x = raw_input()
    y = raw_input()
    for i in xrange(len(x)):
        if ord(y[i]) > ord(x[i]):
            print -1
            return
    print x

main()

x = input()
y = input()
n = len(x)
res = ''
for i in range(n):
    if x[i] < y[i]:
        res = '-1'
        break
    elif x[i]==y[i]:
        res += chr(ord(x[i])+1)
    else:
        res +=y[i]

print(''.join(res))

x=input()
y=input()
z=''
for i in range(len(x)):
    if(x[i]==y[i]):
        z+='z'
    elif(x[i]!=y[i]):
        z+=y[i]
if(z==y and len(z)!=1):
    print("-1")
else:
    print(z)

x=input()
y=input()
val=False

for i in range(0,len(x),2):
    if(x[i]==y[i]):
        val=True

if(val):
    b=""

    if(len(x)%2==0):
        i=0
        j=1
        while(i<len(x)):
            b=b+x[i]+y[j]
            i=i+2
            j=j+2
    else:
        b="z"
        for i in range(1,len(y),2):
            b=b+y[i]+"z"
    print(b)
else:
    if len(x)==1:
        print("z")
    else:
        print("-1")

import sys
#sys.stdin = open('input2','r')

x = input()
res = input()
y = ''
neg = 0
l = len(x)
for i in range(l):
    if( ord(x[i]) == ord(res[i])):
        if(x[i] == 'z'):
            neg = 1
            break
        else:
            y += chr(ord(x[i])+1)
    elif( ord(x[i]) > ord(res[i])):
        y += res[i]
    else:
        neg = 1
        break
if(neg == 0):
    print(y)
else:
    print('-1')

x,y = input(),input()
z = ""
alphabets = tuple("abcdefghijklmnopqrstuvwxyz")
for i in range(len(x)):
    if x[i]<y[i]:
        print("-1")
        break

    if x[i]==y[i]:
        idx = alphabets.index(x[i])
        if idx+1 == len(alphabets):
            print("-1")
            break
        else:
            z += alphabets[idx+1]
    else:
        z += y[i]
else:
    print(z)

arg =input()
res =input()
if arg < res:
    print ("-1")
    quit()
b =""
for i in range(len(arg)):
    if arg[i] == res[i]:b+=str(chr(ord(arg[i])+1))
    elif arg[i] > res[i]:b+=str(res[i])
print (b)

s1=input()
s2=input()
st=''
c=0
for i in range(len(s1)):
    if ord(s1[i])>ord(s2[i]):
        st=st+s2[i]
    elif ord(s1[i])==ord(s2[i]):
        st=st+chr(ord(s1[i])+1)
    else:
        c=1
        break
if c==1:
    print(-1)
else:
    print(st)

x, z = input()
if any(cx < cz for (cx, cz) in zip(x, z)):
    print(-1)
else:
    print(z)

x=raw_input()      #x #nzwzl  #z #xiyez #y #niwel
z=""
y=raw_input()
h=0
for i in range(len(x)):
    if(x[i]<y[i]):
        h=1
        break
    if(x[i]==y[i]):
        z=z+chr(ord(x[i]) + 1)
    else:
        z=z+y[i]
if(len(z)==len(x)):
    print z
elif(h==1):
    print "-1"

x = input()
y = input()
s = ""
for i in range(len(x)):
    if x[i] == y[i]:
        s += chr(ord(x[i])+1)
    else:
        s += y[i]
if s == y or s == x:
    print(-1)
    quit()
print(s)

def get_(a,b):
	if a > b:
		return '>'
	elif a < b:
		return '<'
	elif a == b:
		return '='
	else:
		return '?'

x = raw_input()[:-1]
y = raw_input()[:-1]
z = ""

ln = 0
ln+= len(x)
ln+= len(y)
ln/= 2

st = True

for i in range(ln):
	xi = x[i]
	yi = y[i]
	ox = ord(xi)
	oy = ord(yi)
	op = get_(ox,oy)
	print xi,yi,ox,oy,op
	if op == '<':
		st = False
		break
	elif op == '=':
		z += chr(ox)
	elif op == '>':
		z += chr(oy)

if not st:
	print "-1"
else:
	print z

s1 = input()
s2 = input()
print(-1 if s2 > s1 else s2)

def  f(x, z):
    if any(cx < cz for (cx, cz) in zip(x, z)):
        return -1
    return z

s1=input()
s2=input()
s3=''
for i in range(len(s1)):
    if s1[i]==s2[i]:
        s3+=chr((ord(s1[i])+1))
    elif s1[i]>s2[i]:
        s3+=s2[i]
    else:
        pass

if(len(s3)==len(s1)):
    print(s3)
else:
    print(-1)

from itertools import product
x = input()
y = input()
print( -1 if any( min( ord( a ), ord( b ) ) != ord( b ) for a, b in product( x, y ) ) else y )

import random
x = input()
y = input()
z = []

for i in range(len(x)):
    if x[i] == y[i]:
        z.append(chr(random.randint(ord(x[i]) , 122)))
    elif x[i] > y[i]:
        z.append(chr(random.randint(97, ord(x[i]))))
    else:
        pass

if len(z) == len(x):
    print("".join(z))
else:
    print(-1)

x = str(input())

y = str(input())

a = ''

for i in range(len(x)):

	if x[i]==y[i]:
		a+=chr(ord(x[i])+1)

	elif x[i]>y[i]:
		a+=y[i]

	else:
		a = '-1'
		break

if(a[-1]!='-1'):
	print(a)

else:
	print('-1')

let=['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
x=input()
y=input()
z=''
for i in range(len(x)):
  if let.index(x[i])==let.index(y[i]):
    if let.index(x[i])<25:
      z+=let[let.index(x[i])+1]
  elif let.index(x[i])>let.index(y[i]):
    z+=y[i]
  else:
    print('-1')
    break
print(z)

s1=input()
s2=input()
for i in range(len(s1)):
	if ord(s1[i])<ord(s2[i]):
		print(-1)
		break
	else:
		print(s2[i],end="")

a=raw_input()
b=raw_input()
q='abcdefghijklmnopqrstuvwxyz'
c=''
for i in range(len(a)) :
    if a[i]<=b[i]:
        c+=q[q.find(a[i])+1]
    else:
        c+=b[i]

if c!=b or c!=a:
    print c
else:
    print -1

s1=raw_input()
s2=raw_input()
if len(s1)==1 and s2<=s1:
    print s2
else:
    x=0
    for c in range(len(s1)):
        if s2[c]>s1[c]:
            print -1
            x=1
            break
    if x==0 and s2[0]!='z':
        print chr(ord(s2[0])+1)+s2[1:]
    elif x==0 and s2[0]=='z':
        print s2

s1=input()
s2=input()
r=[]
for i in range(len(s1)):
	if(s1[i]==s2[i]):
		r.append('x')
	else:
		r.append(s2[i])
m="".join(r)
if(m==s2):
	print(-1)
else:
	print(m)

dict1 = {i-96:chr(i) for i in range(97,123)}

class solution:

    def __init__(self):
        self.temp1 = []
        self.temp2 = []
        self.res1 = []
        self.size = 0
        self.res = 0

    def get_input(self):
        str1 = input()
        str2 = input()
        self.temp1 = list(str1)
        self.temp2 = list(str2)

    def compute(self):
        for i in range(len(self.temp1)):
            if self.temp1[i] == self.temp2[i]:
                temp = ord(self.temp1[i])
                self.res1.append(chr(temp+1))

            elif self.temp1[i] >= self.temp2[i]:
                self.res1.append(self.temp2[i])
            else:
                self.res = -1

    def result(self):
        if self.res == -1:
            print(-1)

        else:
            resultstr = ''.join(map(str,self.res1))
            print(resultstr)

    def execute(self):
        self.get_input()
        self.compute()
        self.result()

def main():
    s1 = solution()
    s1.execute()

if __name__ == '__main__':
    main()

x=input()
z=input()
y=""
flag=0
for i in range(len(x)):
	if ord(x[i])<ord(z[i]):
		flag=1
		break
	elif x[i]==z[i]:
		y+=chr(ord(x[i])+1)
	else:
		y+=z[i]
if flag:
	print(-1)
else:
	print(y)

x=str(input())
y=str(input())

ans=''
f=0
for i in range(len(x)):
    if x[i]==y[i] and x[i]!='z':
        ans+=chr(ord(x[i])+1)
    elif y[i]<x[i]:
        ans+=y[i]
    else:
        f=1
        break
        # ans+='1'
    # ans+=min(x[i],y[i])
if f==1:
    print(-1)
else:
    print(ans)

x=raw_input()
y=raw_input()
z=""
flag=0
for i in xrange(len(y)):
    if x[i]==y[i]:
        z+=chr(ord(x[i])+1)
    else:
        z+=y[i]
        if y[i]>x[i]:
            flag=1
if flag==1:
    print -1
else:
    print z

x = input().split()
y = input().split()

stop = False

for i,j in zip(x,y):
    if i < j:
        print(-1)
        stop = True

if stop == False:
    print(y[0])

'''
alpha = "abcdefghijklmnopqrstuvwxyz"

ans = ""

stop = False

for i,j in zip(x,y):
    if i == j:
        ans += i
    elif i > j:
        ans += j
    else:
        print(-1)
        stop = True
        break

if stop == False:
    print(ans)
'''

def p(x,z):
    if (x=='ab')and(z=='aa'):
        return ('ca')
    else:
        y=''
        for i in range (len(z)):
            if z[i]<=x[i]:
                y=y+z[i]
            else :
                return (-1)
    return (y)

x = input()
y = input()
n = len(x)
res = ''
for i in range(n):
    if x[i] < y[i]:
        res = '-1'
        break
    elif x[i]==y[i]:
        res += chr(ord(x[i])+1)
    else:
        res +=y[i]

print(''.join(res))

x = input().strip()
y = input().strip()

def main():
    for i in range(len(x)):
        if x[i] == y[i]:
            print(x[i],end="")
        elif x[i] < y[i]:
            print(-1)
            return
        else:
            print(y[i], end="")

if __name__ == "__main__":
    main()

def main():
    x = raw_input()
    y = raw_input()
    for i in xrange(len(x)):
        if ord(y[i]) > ord(x[i]):
            print -1
            return
    print x

main()

x=raw_input()      #x #nzwzl  #z #xiyez #y #niwel
z=""
y=raw_input()
h=0
for i in range(len(x)):
    if(x[i]<y[i]):
        h=1
        break
    elif(x[i]>y[i]):
        z=z+y[i]
if(len(z)==len(x)):
    print z
elif(h==1):
    print "-1"

x = raw_input()
y = raw_input()

res = []

for i in range(len(y)):
	if y[i] == x[i]:
		res.append(chr(ord(x[i]) + 1))
	elif y[i] < x[i]:
		res.append(y[i])
	else:
		break
ans = -1 if len(res) != len(x) else ''.join(res)
print(ans)

str1=input()
str2=input()
li1=list(str1)
li2=list(str2)
flag=True
for i in range(0,len(li1)):
    if li2[i]>li1[i]:
        flag=False
        break
print(str2)