#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    auto f = [&](int x) {
        cout << "?" << " " << x << endl;
        cout.flush();
        string s; cin >> s;
        return (s == "out");
    };
    
    int ok = -1, ng = 1000 + 1;
    while(ng - ok > 1) {
        int mid = (ok + ng) / 2;
        bool f0 = f(mid), f1 = f(mid + 1);
        if(f0 && f1) {
            ng = mid;
        } else if(!f1) {
            ok = mid + 1;
        } else if(!f0) {
            ok = mid;
        }
    }

    cout << "!" << " " << ok << endl;
    cout.flush();
}