# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

def Binary_Search():
	#初期化
	left = 1
	right = 1000
	ans = 0
	
	#二分探索
	while left <= right:
		mid = (left + right) // 2
		print("?", mid, flush=True)
		s1 = input()
		print("?", mid + 1, flush=True)
		s2 = input()
		if s1 == "safe" and s2 == "safe":
			ans = max(ans, mid + 1)
			left = mid + 1
		elif s1 == "safe" and s2 == "out":
			ans = max(ans, mid)
			left = mid + 1
		elif s1 == "out" and s2 == "safe":
			ans = max(ans, mid + 1)
			left = mid + 1
		else:
			right = mid - 1

	return ans

#処理内容
def main():
	ans = Binary_Search()
	print("!", ans)


if __name__ == '__main__':
	main()