#include<bits/stdc++.h>
#define int long long
using namespace std;
signed main(){
    int ok=0,ng=1001;
    while(ng-ok>1){
        int n=(ok+ng)/2;
        string S,T;
        cout<<"? "<<n<<endl;
        cin>>S;
        cout<<"? "<<n+1<<endl;
        cin>>T;
        if(S=="out" && T=="out")ng=n;
        else ok=n;
    }
    cout<<"! "<<ok<<endl;
}