#include <bits/stdc++.h>
using namespace std;
bool ask(long long l, long long r) {
  cout << l << ' ' << r << '\n';
  cout.flush();
  string res;
  cin >> res;
  return res == "Yes";
}
int main() {
  srand(time(NULL));
  ios_base::sync_with_stdio(false);
  long long n, k;
  cin >> n >> k;
  long long l = 1, r = n;
  while (true) {
    if (r - l > 60ll) {
      long long mid = l + r >> 1;
      if (ask(l, mid)) {
        l = max(1ll, l - k);
        r = min(mid + k, n);
      } else {
        l = max(mid + 1 - k, 1ll);
        r = min(r + k, n);
      }
    } else {
      long long mid = rand() % (r - l + 1) + l;
      if (ask(mid, mid)) return 0;
      l = max(l - k, 1ll);
      r = min(r + k, n);
    }
  }
}
