#include <bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count() *
               ((uint64_t) new char | 1));
long long N, K;
bool query(long long L, long long R) {
  cout << L << ' ' << R << endl;
  string answer;
  cin >> answer;
  if (answer == "Bad") exit(0);
  if (L == R && answer == "Yes") exit(0);
  return answer == "Yes";
}
int main() {
  cin >> N >> K;
  long long low = 1, high = N;
  while (true) {
    bool go_for_it = high - low <= 6 * K;
    if (go_for_it) {
      long long location = uniform_int_distribution<long long>(low, high)(rng);
      query(location, location);
    } else {
      long long mid = (low + high) / 2;
      if (query(low, mid))
        high = mid;
      else
        low = mid + 1;
    }
    low = max(low - K, 1LL);
    high = min(high + K, N);
  }
}
