#include <bits/stdc++.h>
using namespace std;
bool ask(long long st, long long en = 0) {
  cout << st + 1 << ' ' << max(en, st + 1) << endl;
  string s;
  cin >> s;
  return s == "Yes";
}
int main() {
  ios_base ::sync_with_stdio(false), cout.tie(0), cin.tie(0), srand(time(0));
  int k;
  long long n;
  cin >> n >> k;
  long long L = 0, R = n;
  while (L < R) {
    if (R - L > max(k << 2 | 1, 4)) {
      long long mid = L + R >> 1;
      ask(L, mid) ? R = mid : L = mid;
    } else if (ask(L + rand() % (R - L)))
      break;
    L = max(L - k, 0LL), R = min(R + k, n);
  }
  return 0;
}
