#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10, mod = 1e9 + 7;
int k;
long long n, l = 1, r;
void ask() {
  long long x = (l + r) / 2;
  cout << l << " " << x << endl;
  string s;
  cin >> s;
  if (s == "Yes") {
    l = max(l - k, 1ll);
    r = min(n, x + k);
  } else {
    l = max(x + 1 - k, 1ll);
    r = min(r + k, n);
  }
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  srand(time(NULL));
  cin >> n >> k;
  r = n;
  int cur = 0;
  while (true) {
    if (cur++ % 2) {
      ask();
    } else {
      int id = rand() % (r - l + 1);
      cout << l + id << " " << l + id << endl;
      string s;
      cin >> s;
      if (s == "Yes") return 0;
      l = max(l - k, 1ll);
      r = min(r + k, n);
    }
  }
  return 0;
}
