#include <bits/stdc++.h>
using namespace std;
long long n, k;
mt19937_64 mt(time(0));
bool query(long long from, long long to) {
  from = max(from, 1ll);
  to = min(to, n);
  cout << from << ' ' << to << endl;
  string ans;
  cin >> ans;
  assert(ans == "Yes" || ans == "No");
  if (ans == "Yes" && from == to) {
    exit(0);
  }
  return ans == "Yes";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin >> n >> k;
  long long from = 1, to = n;
  while (true) {
    if (to < from + 50) {
      long long pos = mt() % (to - from + 1) + from;
      query(pos, pos);
      from = max(from - k, 1ll);
      to = min(to + k, n);
      continue;
    }
    long long mid = (from + to) / 2;
    if (query(from, mid)) {
      to = mid;
    } else {
      from = mid + 1;
    }
    from = max(from - k, 1ll);
    to = min(to + k, n);
  }
  return 0;
}
