func_code_string: #include <bits/stdc++.h>   using namespace std;   bool query(int x, int y) {     cout <<  ?   << x <<     << y << endl;     char resp;     cin >> resp;     if (resp ==  e ) exit(0);     return resp ==  x ;   }   void answer(int v) {     cout <<  !   << v << endl;     return;   }   void solve() {     int k = -1;     ;     for (int i = 0; i < 30; i++) {       int x = (1 << (i + 1)), y = (1 << i);       if (!query(x, y)) {         k = i;         break;       }     }     if (k == -1) {       answer(1);       return;     }     int l = (1 << k);     int u = (1 << (k + 1));     while (u - l > 2) {       int mid = (u + l) / 2;       if (!query(mid, mid / 2))         u = mid;       else         l = mid;     }     if (!query(u, 1))       answer(u);     else       answer(u - 1);     return;   }   int main() {     string msg;     while (cin >> msg, msg !=  end ) {       solve();     }     return 0;   }   