a = input() b = input() c = input() d = input() if a == "z": print("a",end=" ") else: print(chr(ord(a)+1),end=" ") if b == "z": print("a",end=" ") else: print(chr(ord(b)+1),end=" ") if c == "z": print("a",end=" ") else: print(chr(ord(c)+1),end=" ") if d == "z": print("a",end=" ") else: print(chr(ord(d)+1),end=" ")