alpha = input()

S = 'abcdefghijklmnopqrstuvwxyz'
seen = set()
orig = ''

for s in S:
    if s != alpha:
        print(f"? {alpha}{s}", flush=True)
        orig = s
        break

_, s = input().split()
seen.add(s[1])

for _ in range(100):
    for i in range(26):
        if S[i] not in seen:
            print(f"? {orig}{S[i]}", flush=True)
            seen.add(S[i])
            break

    c, s = input().split()

    if c == '!':
        exit()
    else:
        seen.add(s[1])