#include <bits/stdc++.h>
using namespace std;
int main() {
  mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
  long long n, k;
  cin >> n >> k;
  string s;
  long long lo = 1, hi = n;
  while (1) {
    long long mid = lo + hi >> 1;
    if (hi - lo <= 50) {
      long long guess = rng() % (hi - lo + 1) + lo;
      cout << guess << ' ' << guess << endl;
      cin >> s;
      if (s == "Yes") exit(0);
      lo = max(1ll, lo - k), hi = min(n, hi + k);
      continue;
    }
    cout << lo << ' ' << mid << endl;
    cin >> s;
    if (s == "Yes")
      lo = max(lo - k, 1ll), hi = min(mid + k, n);
    else
      lo = max(mid - k, 1ll), hi = min(hi + k, n);
  }
}
