#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long Query(long long L, long long R) {
  cout << L << " " << R << endl;
  fflush(stdout);
  string s;
  cin >> s;
  return s == "Yes";
}
int32_t main() {
  long long n, k;
  cin >> n >> k;
  long long L = 1, R = n;
  while (true) {
    if (R - L + 1 <= 4 * k + 7) {
      long long M = L + rng() % (R - L + 1);
      if (Query(M, M)) {
        return 0;
      } else {
        L = max(1LL, L - k);
        R = min(n, R + k);
      }
    } else {
      long long M = L + ((R - L) >> 1);
      if (Query(L, M)) {
        L = max(1LL, L - k);
        R = min(n, M + k);
      } else {
        L = max(1LL, M - k);
        R = min(n, R + k);
      }
    }
  }
}
