#include <bits/stdc++.h>
using namespace std;
long long n;
int k;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  srand(time(0));
  cin >> n >> k;
  long long lo = 1, hi = n, mid;
  string s;
  while (true) {
    if (hi - lo + 1 <= 41) {
      int i = rand() % (hi - lo + 1);
      cout << lo + i << " " << lo + i << endl;
      cin >> s;
      if (s == "Yes") {
        return 0;
      }
      assert(s != "Bad");
    } else {
      mid = (lo + hi) / 2;
      cout << lo << " " << mid << endl;
      cin >> s;
      assert(s != "Bad");
      if (s == "Yes") {
        hi = mid;
      } else {
        lo = mid + 1;
      }
    }
    hi = min(n, hi + k);
    lo = max(1ll, lo - k);
  }
  return 0;
}
