from string import ascii_lowercase
a = ascii_lowercase
from collections import defaultdict
mp = defaultdict(list)
for s in a:
    for t in a:
        mp[s].append(s+t)

alpha = input()

while True:
    print('?',mp[alpha].pop())
    res = input()
    if res == '! WIN':
        exit()        
    content = res.split()[1]
    alpha = content[1]