n = int(input())
X = "abcdefghijklmnopqrstuvwxy"
ans = ["?" for _ in range(n)]
for i in range(n):
	cnt = [0 for _ in range(25)]
	z = ["z" for _ in range(n)]
	for x in X:
		z[i] = x
		print("?", "".join(z), flush=True)
		m = int(input())
		cnt[ord(x) - ord("a")] = m
	cnts = set(cnt)
	if len(cnts) == 1:
		ans[i] = "z"
	else:
		max_cnt = max(cnt)
		idx = cnt.index(max_cnt)
		ans[i] = X[idx] 

print("!", "".join(ans), flush=True)