#include <bits/stdc++.h>
using namespace std;
int main() {
  srand(time(NULL));
  long long n, k;
  cin >> n >> k;
  int cnt = 0;
  long long l = 1, r = n;
  while (true) {
    while (r - l > 44) {
      long long mid = (r + l) / 2;
      cout << l << " " << mid << endl;
      cnt++;
      cout.flush();
      string res;
      cin >> res;
      if (res == "Yes") {
        l = max(l - k, 1LL);
        r = min(mid + k, n);
      } else if (res == "No") {
        l = max(mid + 1 - k, 1LL);
        r = min(r + k, n);
      } else {
        if (cnt > 4500) {
          while (true) {
            cout << "1 1" << endl;
          }
        }
        return 0;
      }
    }
    int rn = rand() % (r - l + 1);
    cout << l + rn << " " << l + rn << endl;
    cnt++;
    cout.flush();
    string res;
    cin >> res;
    if (res == "Yes") {
      return 0;
    } else if (res == "No") {
      l = max(l - k, 1LL);
      r = min(r + k, n);
    } else {
      if (cnt > 4500) {
        while (true) {
          cout << "1 1" << endl;
        }
      }
      return 0;
    }
  }
}
