written = set()

alpha = input()
assert ord('a') <= ord('alpha') <= ord('z')

pre = alpha

while True:
	S = pre + alpha
	print('?', S, flush=True)
	written.add(S)
	
	cmd, T = input().split()
	
	if cmd == '?':
		assert len(T) == 2
		assert all(ord('a') <= ord(t) <= ord('z') for t in T)
		assert T not in written
		assert S[1] == T[0]
		
		pre = T[1]
	
	if cmd == '!':
		exit()