#include <bits/stdc++.h>
using namespace std;
long long n, k;
int main() {
  cin >> n >> k;
  long long low = 1, high = n;
  srand(time(NULL));
  while (true) {
    while (high - low > 50) {
      long long mid = (low + high) / 2;
      cout << low << " " << mid << "\n";
      fflush(stdout);
      string s;
      cin >> s;
      if (s == "Yes") {
        high = min(mid + k, n);
        low = max(1LL, low - k);
      } else {
        low = max(1LL, mid - k);
        high = min(high + k, n);
      }
    }
    long long guess = rand() % (high - low + 1) + low;
    cout << guess << " " << guess << "\n";
    fflush(stdout);
    string s;
    cin >> s;
    if (s == "Yes") return 0;
    low = max(1LL, low - k);
    high = min(n, high + k);
  }
  return 0;
}
