from operator import itemgetter
from itertools import *
from bisect import *
from collections import *
from heapq import *
import sys

sys.setrecursionlimit(10 ** 6)

def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def SI(): return sys.stdin.readline()[:-1]
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
int1 = lambda x: int(x) - 1
def MI1(): return map(int1, sys.stdin.readline().split())
def LI1(): return list(map(int1, sys.stdin.readline().split()))
p2D = lambda x: print(*x, sep="\n")
dij = [(1, 0), (0, 1), (-1, 0), (0, -1)]

memo={}
def ask(m):
    if m in memo:ret=memo[m]
    else:
        print("?",m,flush=True)
        ret=SI()=="safe"
        memo[m]=ret
    if ret:return m
    if m+1 in memo:ret=memo[m+1]
    else:
        print("?",m+1,flush=True)
        ret=SI()=="safe"
        memo[m+1]=ret
    if ret:return m+1
    return -1

l=0
r=1001
while l+1<r:
    m=(l+r)//2
    ret=ask(m)
    if ret==-1:r=m
    else:l=ret
print("!",l,flush=True)