#include <bits/stdc++.h>
using namespace std;
int main() {
  srand(time(0));
  long long n;
  int k;
  cin >> n >> k;
  int rem = 4500;
  long long l = 1, r = n;
  while (1) {
    string s;
    if (r - l + 1 <= 50) {
      long long a = rand() % (r - l + 1) + l;
      cout << a << " " << a << endl;
      cin >> s;
      if (s == "Yes") return 0;
      l = max(l - k, 1ll);
      r = min(n, r + k);
    } else {
      long long mid = l + (r - l) / 2;
      cout << l << " " << mid << endl;
      cin >> s;
      if (s == "Yes") {
        if (l == mid) return 0;
        r = min(n, mid + k), l = max(1ll, l - k);
      } else if (s == "No")
        l = max(1ll, mid - k), r = min(n, r + k);
    }
  }
}
