#include <bits/stdc++.h>
using namespace std;

bool angry(int N){
    cout << "? " << N << endl;
    string s;
    cin >> s;
    return (s == "out");
}

int main(){
    int ok = 0, ng = 1000;
    while(ng-ok>1){
        int mid = (ng+ok)/2;
        (angry(mid) && angry(mid+1) ? ng : ok) = mid;
    }
    cout << "! " << ok << endl;
    return 0;
}