#include <bits/stdc++.h>
using namespace std;
string info = "";
int main() {
  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
  long long int n, k;
  cin >> n >> k;
  long long int st = 1, ed = n;
  while (1) {
    long long int d = ed - st;
    if (d <= 40) {
      long long int x0 = uniform_int_distribution<long long int>(st, ed)(rng);
      cout << x0 << ' ' << x0 << endl;
      cin >> info;
      if (info == "Yes") break;
    } else {
      long long int mid = (st + ed) >> 1LL;
      cout << st << ' ' << mid << endl;
      cin >> info;
      if (info == "Yes")
        ed = mid;
      else
        st = mid + 1;
    }
    st = max(1LL, st - k);
    ed = min(n, ed + k);
  }
  return 0;
}
