#include <bits/stdc++.h>
using namespace std;
bool ask(long long a, long long b) {
  cout << a << ' ' << b << endl;
  string ans;
  cin >> ans;
  return (ans == "Yes");
}
int main() {
  mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
  long long n;
  int k;
  cin >> n >> k;
  long long a = 1;
  long long b = n;
  while (true) {
    a = max((long long)1, a - k);
    b = min(n, b + k);
    long long len = b - a + 1;
    if (len <= 50) {
      long long pos = uniform_int_distribution<long long>(a, b)(rng);
      if (ask(pos, pos)) break;
    } else {
      long long mid = (a + b) >> 1;
      if (ask(a, mid))
        b = mid;
      else
        a = mid + 1;
    }
  }
}
