func_code_string: #include <bits/stdc++.h>   using namespace std;   char inp[5];   void try_catch(long long int l, long long int r) {     long long int mid = l + rand() % (r - l + 1);     printf( %lld %lld n , mid, mid);     fflush(stdout);     scanf( %s , inp);     if (inp[0] ==  Y ) exit(0);   }   int main() {     srand(time(NULL));     long long int n, k;     cin >> n >> k;     long long int l = 1, r = n;     while (1) {       while (r - l < 60) {         try_catch(max(1LL, l - k), min(n, r + k));         l = max(1LL, l - 2 * k);         r = min(n, r + 2 * k);       }       long long int mid = (l + r) / 2;       printf( %lld %lld n , l, mid);       fflush(stdout);       scanf( %s , inp);       if (inp[0] ==  Y ) {         if (l == mid) exit(0);         r = min(n, mid + k);         l = max(1LL, l - k);       } else {         l = max(1LL, mid - k);         r = min(n, r + k);       }     }     return 0;   }   