a=input()
print("?",a+"a")
used={a+"a"}
while True:
	judge=input().split()
	if judge[0]=="!":
		break
	used.add(judge[1])
	for i in range(27):
		if i==26:
			print("!")
			exit()
		if judge[1][1]+chr(ord("a")+i) not in used:
			print("?",judge[1][1]+chr(ord("a")+i))
			used.add(judge[1][1]+chr(ord("a")+i))
			break