#include <bits/stdc++.h>
using namespace std;
bool check(long long n, long long k) {
  long long l = 1, r = n;
  string q;
  while (r - l >= 50) {
    long long mid = (l + r) >> 1;
    cout << l << ' ' << mid << endl;
    cout.flush();
    cin >> q;
    if (q[0] == 'Y') {
      l = max(1ll, l - k);
      r = min(n, mid + k);
    } else {
      l = max(mid + 1 - k, 1ll);
      r = min(n, r + k);
    }
  }
  long long kick = (rand() * rand() * rand() * rand());
  if (kick < 0) kick *= -1;
  long long len = r - l + 1;
  ;
  ;
  kick = kick % len;
  ;
  cout << l + kick << ' ' << l + kick << endl;
  cout.flush();
  cin >> q;
  if (q[0] == 'Y')
    return true;
  else
    return false;
}
signed main() {
  srand(time(NULL));
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long n, k;
  cin >> n >> k;
  while (true) {
    if (check(n, k)) return 0;
  }
}
