func_code_string: #include <bits/stdc++.h>   using namespace std;   long long qu(long long a, long long b) {     cout <<  ?   << a <<     << b << endl;     fflush(stdout);     string s;     cin >> s;     if (s[0] ==  x ) return 1;     return 2;   }   int main() {     string s;     while (1) {       cin >> s;       if (s !=  start ) return 0;       long long l = 1;       if (qu(0, 1) == 1) {         cout <<  ! 1 n ;         fflush(stdout);         continue;       }       while (qu(2 * l, l) == 1) l = l * 2LL;       long long r = min((l * 2LL), 1000000000LL);       l++;       long long x = l;       while (l < r) {         long long mid = (l + r) / 2;         if (qu(l - 1, mid) == 2)           l = mid + 1;         else           r = mid;       }       cout <<  !   << l <<   n ;       fflush(stdout);     }     return 0;   }   