#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  srand(time(0));
  long long n, k;
  cin >> n >> k;
  long long l = 1, r = n;
  bool found = false;
  while (!found) {
    if (r - l + 1 <= 50) {
      long long x = l + rand() % (r - l + 1);
      cout << x << " " << x << endl;
      cout.flush();
      string answer;
      cin >> answer;
      if (answer == "Yes") {
        found = true;
      } else if (answer == "Bad") {
        return 0;
      } else {
        l = max(1LL, l - k);
        r = min(n, r + k);
      }
    } else {
      long long mid = l + (r - l) / 2;
      cout << l << " " << mid << endl;
      cout.flush();
      string answer;
      cin >> answer;
      if (answer == "Yes") {
        l = max(1LL, l - k);
        r = min(n, mid + k);
      } else if (answer == "Bad") {
        return 0;
      } else {
        l = max(1LL, mid - k);
        r = min(n, r + k);
      }
    }
  }
  return 0;
}
