#include <bits/stdc++.h>
using namespace std;
int main() {
  srand(time(NULL));
  long long n, k;
  cin >> n >> k;
  long long beg = 1;
  long long end = n;
  while (1) {
    if (end - beg == 0) {
      cout << end << " " << end << endl;
      string s;
      cin >> s;
      break;
    }
    if (end - beg <= 50) {
      long long pos = rand() % (end - beg + 1);
      cout << beg + pos << " " << beg + pos << endl;
      string result;
      cin >> result;
      if (result == "Yes") {
        break;
      } else {
        beg = max(1ll, beg - 10);
        end = min(n, end + 10);
      }
    } else {
      long long mid = (beg + end) / 2;
      cout << beg << " " << mid << endl;
      string result;
      cin >> result;
      if (result == "Yes") {
        beg = max(1ll, beg - 10);
        end = min(n, mid + 10);
      } else {
        beg = max(1ll, mid - 10);
        end = min(n, end + 10);
      }
    }
  }
}
