#include <bits/stdc++.h>
using namespace std;
int main(){
  int tv = 0;
  int fv = 1000;
  while (fv - tv > 1){
    int mid = (tv + fv) / 2;
    cout << "? " << mid << endl;
    string S1;
    cin >> S1;
    cout << "? " << mid + 1 << endl;
    string S2;
    cin >> S2;
    if (S1 == "out" && S2 == "out"){
      fv = mid;
    } else {
      tv = mid;
    }
  }
  int ans = tv;
  while (1){
    cout << "? " << ans << endl;
    string S;
    cin >> S;
    if (S == "out"){
      ans--;
    } else {
      break;
    }
  }
  cout << "! " << ans << endl;
}