#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  srand(time(NULL));
  long long n, k;
  cin >> n >> k;
  long long lo = 1, hi = n + 1;
  string ans;
  long long lastRange = n + 2;
  while (1) {
    if ((hi - lo) < lastRange) {
      lastRange = (hi - lo);
      long long mi = max(lo + 1, (hi + lo) / 2);
      cout << lo << " " << mi - 1 << endl;
      cout.flush();
      cin >> ans;
      if (ans == "Yes") {
        if (lo == mi - 1) {
          break;
        }
        lo = max(lo - k, 1LL);
        hi = min(mi + k, n + 1);
      } else {
        lo = max(mi - k, 1LL);
        hi = min(hi + k, n + 1);
      }
    } else {
      long long len = (hi - lo);
      long long p = rand() % len;
      long long guess = lo + p;
      cout << guess << " " << guess << endl;
      cout.flush();
      cin >> ans;
      if (ans == "Yes") {
        break;
      } else {
        lo = max(lo - k, 1LL);
        hi = min(hi + k, n + 1);
      }
      lastRange = (hi - lo + 1);
    }
  }
  return 0;
}
