func_code_string: #include <bits/stdc++.h>   using namespace std;   bool ask(long long l, long long r) {     printf( %lld %lld n , l, r);     fflush(stdout);     char x[4];     scanf(  %s , x);     return x[0] ==  Y ;   }   long long n, k;   int main() {     cin >> n >> k;     long long l = 1, r = n;     srand(time(0));     while (1) {       if (r - l + 1 <= 50) {         long long q = l + rand() % (r - l + 1);         if (ask(q, q)) return 0;         l = max(1LL, l - k);         r = min(n, r + k);       } else {         long long md = l + ((r - l) >> 1);         if (ask(l, md)) {           l = max(1LL, l - k);           r = min(n, md + k);         } else {           l = max(1LL, md + 1 - k);           r = min(n, r + k);         }       }     }   }   