import sys, re from collections import deque, defaultdict, Counter from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement from operator import itemgetter, mul from copy import deepcopy from string import ascii_lowercase, ascii_uppercase, digits from bisect import bisect, bisect_left from heapq import heappush, heappop from functools import reduce def input(): return sys.stdin.readline().strip() def INT(): return int(input()) def MAP(): return map(int, input().split()) def LIST(): return list(map(int, input().split())) def ZIP(n): return zip(*(MAP() for _ in range(n))) sys.setrecursionlimit(10 ** 9) INF = float('inf') mod = 10 ** 9 + 7 l = -1 r = 1000 while l+1 != r: m = (l+r)//2 print("? {}".format(m+1), flush=True) ret1 = input() print("? {}".format(m+2), flush=True) ret2 = input() if ret1 == "out" and ret2 == "out": r = m else: l = m print("! {}".format(r))