func_code_string: #include <bits/stdc++.h>   using namespace std;   long long bins(long long l, long long r) {     while (l + 1 < r) {       long long m = (l + r) >> 1;       cout <<  ?   << l <<     << m << endl;       cout.flush();       char c;       cin >> c;       if (c ==  e ) return 0;       if (c ==  y ) {         l = m;       } else {         r = m;       }     }     return r;   }   signed main() {     string s;     cin >> s;     long long x, y;     while (s ==  start ) {       x = 0, y = 1;       char c =  y ;       bool z = false;       while (c !=  x ) {         if (!z)           z = true;         else           x = y, y *= 2;         cout <<  ?   << x <<     << y << endl;         cout.flush();         cin >> c;         if (c ==  e ) return 0;       }       long long p = bins(x, y);       cout <<  !   << p << endl;       cout.flush();       cin >> s;       if (s ==  mistake ) {         return 0;       }       if (s ==  end ) return 0;     }     return 0;   }   