func_code_string: #include <bits/stdc++.h>   using namespace std;   string s;   void rd() {     cin >> s;     if (s !=  start ) exit(0);   }   int q(int x, int y) {     cout <<  ?   << x <<     << y << endl;     cin >> s;     if (s[0] ==  x ) return 1;     if (s[0] ==  y ) return 0;     exit(0);   }   int main() {     int i, l, r;     while (1) {       rd();       if (q(0, 1)) {         cout <<  !   << 1 << endl;         continue;       }       for (i = 1; 1; i <<= 1)         if (q(i, i + i)) break;       for (l = i + 1, r = i + i; l < r;) {         i = ((long long)l + r) / 2;         if (q(i, r))           l = i + 1;         else           r = i;       }       cout <<  !   << l << endl;     }     return 0;   }   