s=input().split() a=s[0] b=s[1] c=s[2] d=s[3] if ord(a)+1 >=123: print('a',end=" ") else: print(chr(ord(a)+1),end=" ") if ord(b)+1 >=123: print('a',end=" ") else: print(chr(ord(b)+1),end=" ") if ord(c)+1 >=123: print('a',end=" ") else: print(chr(ord(c)+1),end=" ") if ord(d)+1 >=123: print('a',end=" ") else: print(chr(ord(d)+1),end=" ")