#include <bits/stdc++.h>
using namespace std;
int main() {
  srand(time(0));
  long long n;
  int k;
  cin >> n >> k;
  long long l = 1, r = n;
  while (true) {
    while (r - l >= 4 * k) {
      long long m = (r + l) / 2;
      cout << l << ' ' << m << endl;
      string res;
      cin >> res;
      if (res == "Yes") {
        l = max(1LL, l - k);
        r = min(m + k, n);
      } else if (res == "No") {
        l = max(1LL, m - k + 1);
        r = min(r + k, n);
      } else {
        return 0;
      }
    }
    long long p = rand() % (r - l + 1) + l;
    cout << p << ' ' << p << endl;
    string res;
    cin >> res;
    if (res == "Yes") {
      return 0;
    }
    l = max(1LL, l - k);
    r = min(r + k, n);
  }
}
