#include <bits/stdc++.h>
using namespace std;
long long i, j, k;
int main() {
  long long n, k;
  cin >> n >> k;
  if (k == 0) k = 1;
  long long l = 1, r = n;
  srand(time(NULL));
  while (true) {
    while ((r - l) > 6 * k) {
      long long m = (l + r) / 2;
      cout << l << " " << m << " " << '\n';
      cout.flush();
      string ans;
      cin >> ans;
      if (ans == "Yes") {
        l = max(1LL, l - k);
        r = min(n, m + k);
      } else if (ans == "No") {
        l = max(1LL, m - k);
        r = min(n, r + k);
      }
    }
    long long rr = rand() % ((r - l) + 1);
    cout << (l + rr) << " " << (l + rr) << '\n';
    cout.flush();
    string ss;
    cin >> ss;
    if (ss == "Yes") {
      return 0;
    } else if (ss == "No") {
      l = max(1LL, l - k);
      r = min(n, r + k);
    }
  }
  return 0;
}
