func_code_string: #include <bits/stdc++.h>   using namespace std;   string s;   long long int n, k;   long long int L, R;   bool query(long long int l, long long int r) {     l = max(1LL, l);     r = min(n, r);     cout << l <<     << r << endl;     cin >> s;     if (s ==  Bad ) exit(0);     if (s ==  Yes ) {       if (l == r) exit(0);       return true;     }     return false;   }   int main() {     ios_base::sync_with_stdio(0);     srand(time(NULL));     string s;     cin >> n >> k;     L = 1;     R = n;     while (true) {       long long int len = (R - L + 1);       if (len <= 5 * k + 4) {         len = rand() % len;         query(L + len, L + len);         L = max(1LL, L - k);         R = min(n, R + k);       } else {         long long int M = (L + R) / 2;         if (query(L, M)) {           L = L - k;           R = M + k;         } else {           L = M - k;           R = R + k;         }       }       L = max(1LL, L);       R = min(n, R);     }     exit(0);   }   