a = input()
S = a + "a"
print("?", S)
done = [False for _ in range(26)]
done[0] = True
while True:
    f,t = input().split()
    if f=="!":
        break
    id = ord(t[1])-97
    done[id] = True
    for i in range(26):
        if not done[i]:
            S = t[1]+"a"
            done[i] = True
            break
    print("?",S)