#include <bits/stdc++.h>
using namespace std;
long long n, k, p;
bool query(long long a, long long b) {
  cout << a << " " << b << '\n';
  fflush(stdout);
  string s;
  cin >> s;
  if (s == "Bad") exit(0);
  return s == "Yes";
}
long long rand(long long a, long long b) { return rand() % (b - a + 1) + a; }
int main() {
  srand(time(0));
  cin >> n >> k;
  long long i = 1, j = n, rep = 4500;
  while (rep--) {
    if (j - i + 1 <= 50) {
      long long d = rand(max(1ll, i - k), min(n, j + k));
      if (query(d, d)) return 0;
      i = max(1ll, i - k);
      j = min(n, j + k);
      continue;
    }
    long long m = (i + j) / 2;
    if (query(i, m)) {
      i = max(1ll, i - k);
      j = min(n, m + k);
    } else {
      i = max(1ll, m - k);
      j = min(n, j + k);
    }
  }
  return 0;
}
