#include <bits/stdc++.h>   using namespace std;   const long long mod = 998244353;   int mx = (int)1e9;   char an;   void ask_query(int i, int j) {     cout <<  ?   << i <<     << j << endl;     cin >> an;     if (an ==  e ) exit(0);   }   int solbin(int l, int r) {     if (r == l + 1) return r;     int mid = (l + r) / 2;     ask_query(l, mid);     if (an ==  x ) {       return solbin(l, mid);     } else {       return solbin(mid, r);     }   }   int sol(int shift, int en) {     if (en == 2) {       ask_query(shift, shift + 1);       if (an ==  y ) {         return shift + 2;       } else {         return shift + 1;       }     }     an =  y ;     int i = 0, j = 2;     int it = 0;     while (an !=  x  && 2 * j < en) {       if (it != 0) {         i = j;         j = min(2 * j, en);       }       ask_query(shift + i, shift + j);       it++;     }     if (2 * j >= en && an !=  x ) {       i = j;       j = en;     }     return solbin(shift + i, shift + j);   }   void solve() {     string s;     cin >> s;     while (s ==  start ) {       int ans = sol(0, mx);       cout <<  !   << ans << endl;       cin >> s;     }   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     long long t;     t = 1;     while (t--) {       solve();     }   }   