#include <bits/stdc++.h>
#include <chrono>
using namespace std;
#define reps(i,s,n) for(int i = s; i < n; i++)
#define rep(i,n) reps(i,0,n)
#define Rreps(i,n,e) for(int i = n - 1; i >= e; --i)
#define Rrep(i,n) Rreps(i,n,0)
#define ALL(a) a.begin(), a.end()
#define fi first
#define se second
typedef long long ll;
typedef vector<ll> vec;
typedef vector<vec> mat;

ll N,M,H,W,Q,K,A,B;
string S;
typedef pair<ll, ll> P;
const ll INF = (1LL<<58);

bool if_safe(int a){
    cout<<"? "<<a<<endl;
    string s;
    cin>>s;
    return s == "safe";
}
int main() {
    cout<<"? 1"<<endl;
    cin>>S;
    if(S == "out"){
        cout<<"! 0"<<endl;
    }else{
        int l = 1, r = 1000;
        while(r - l > 1){
            int cen = (r + l) / 2;
            bool a = if_safe(cen), b = if_safe(cen + 1);
            if((!a) && (!b)){
                r = cen;
            }else{
                l = cen + b;
            }
        }
        cout<<"! "<<l<<endl;
    }
}