#include <bits/stdc++.h>
using namespace std;
#define modulo 998244353
#define mod(mod_x) ((((long long)mod_x+modulo))%modulo)
#define Inf 2000000005

bool get(int m){
	cout<<"? "<<m<<endl;
	
	string s;
	cin>>s;
	if(s=="safe")return true;
	return false;
}

int main(){
	
	int ok = 0,ng = 1001;
	
	while(ng-ok>2){
		int mid = (ok+ng)/2;		
		if(get(mid+1)){
			ok = mid+1;
			continue;
		}
		if(get(mid)){
			ok = mid;
			continue;
		}
		ng = mid;
	}
	
	if(get(ok+1)){
		cout<<"! "<<ok+1<<endl;
	}
	else cout<<"! "<<ok<<endl;
	
	return 0;
}