#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long n, k;
string ans;
signed main() {
  cin >> n >> k;
  if (n == 1) {
    cout << 1 << " " << 1 << "\n";
    cin >> ans;
    return 0;
  }
  long long lo = 1, hi = n;
  while (lo < hi) {
    long long mid = (lo + hi + 1) / 2;
    cout << lo << " " << mid << "\n";
    cin >> ans;
    assert(ans != "Bad");
    if (ans == "Yes") {
      if (lo == mid) return 0;
      hi = min(n, mid + k);
      lo = max(1LL, lo - k);
    } else {
      lo = max(1LL, mid - k + 1);
      hi = min(n, hi + k);
    }
    if (hi - lo < 100) {
      long long x = lo + rng() % (hi - lo + 1);
      cout << x << " " << x << "\n";
      cin >> ans;
      assert(ans != "Bad");
      if (ans == "Yes") return 0;
      lo = max(1LL, lo - k);
      hi = min(n, hi + k);
    }
  }
  cout << lo << " " << lo << "\n";
  cin >> ans;
  return 0;
}
