#include <bits/stdc++.h>
using namespace std;
const int INF = (int)1e9 + 10;
const int MOD = (int)1e9 + 7;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  srand(time(NULL));
  string tmp;
  long long n, k;
  cin >> n >> k;
  long long l = 1, r = n, mid;
  for (int i = 0; i < 4500; i++) {
    if (r - l <= 40) {
      long long guess = l + rand() % (r - l + 1);
      cout << guess << " " << guess << "\n";
      cout.flush();
      cin >> tmp;
      if (tmp == "Yes") return 0;
    } else {
      mid = (l + r) >> 1;
      cout << l << " " << mid << "\n";
      cout.flush();
      cin >> tmp;
      if (tmp == "Yes")
        r = mid;
      else
        l = mid + 1;
    }
    l -= min(k, l - 1);
    r += min(k, n - r);
  }
  return 0;
}
