#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  srand(time(0));
  long long n;
  int k;
  cin >> n >> k;
  long long lef = 1, rig = n;
  for (int rep = 1; rep <= 4500; rep++) {
    if (lef == rig) {
      cout << lef << ' ' << rig << endl;
      string s;
      cin >> s;
      exit(0);
    }
    if (rig - lef > max(4 * k, 1)) {
      long long mid = (lef + rig) / 2;
      cout << lef << ' ' << mid << endl;
      string s;
      cin >> s;
      if (s == "Yes")
        lef = max(lef - k, 1ll), rig = min(mid + k, n);
      else
        lef = max(1ll, mid + 1ll - k), rig = min(n, rig + k);
    } else {
      long long pos = rand() % (rig - lef + 1) + lef;
      cout << pos << ' ' << pos << endl;
      string s;
      cin >> s;
      if (s == "Yes") exit(0);
      lef = max(lef - k, 1ll), rig = min(rig + k, n);
    }
  }
  return 0;
}
