#include <bits/stdc++.h>
using namespace std;
template <typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> a) {
  return o << a.first << ' ' << a.second;
}
template <typename A, typename B>
istream& operator>>(istream& o, pair<A, B>& a) {
  return o >> a.first >> a.second;
}
const int mod = 1e9 + 7, abc = 864197532, N = 200087, logN = 17, K = 333;
auto SEED = chrono::steady_clock::now().time_since_epoch().count();
mt19937 rng(SEED);
bool ask(long long int l, long long int r) {
  cout << l << ' ' << r << endl;
  string s;
  cin >> s;
  if (l == r && s == "Yes") exit(0);
  return s == "Yes";
}
int main() {
  long long int n, k;
  cin >> n >> k;
  long long int l = 1, r = n + 1;
  int t = 4500;
  while (t--) {
    if (r - l <= k * 4 + 7) {
      long long int tmp =
          uniform_int_distribution<long long int>(l, r - 1)(rng);
      ask(tmp, tmp);
      l = max(l - k, 1ll);
      r = min(r + k, n + 1);
    } else {
      long long int mid = l + r >> 1;
      if (ask(l, mid - 1)) {
        r = mid;
      } else {
        l = mid;
      }
      l = max(l - k, 1ll);
      r = min(r + k, n + 1);
    }
  }
}
