def interactive_game():
    import sys
    input = sys.stdin.read
    data = input().split()
    
    alpha = data[0]
    
    used_strings = set()
    last_char = alpha
    
    for i in range(26):
        next_char = chr(ord('a') + i)
        new_string = last_char + next_char
        if new_string not in used_strings:
            used_strings.add(new_string)
            print(f"? {new_string}")
            sys.stdout.flush()
        
        response = input().strip()
        if response == "! WIN" or response == "! LOSE":
            break
        
        # Update last_char to the second character of the string written by the system
        if response.startswith("?"):
            last_char = response[2]
        else:
            break
    
if __name__ == "__main__":
    interactive_game()