#include <bits/stdc++.h>
using namespace std;
bool get(long long l, long long r) {
  cout << l << " " << r << endl;
  string res;
  cin >> res;
  if (res == "Yes")
    return true;
  else
    return false;
}
int main() {
  srand((int)time(NULL));
  long long n, k, l, r;
  cin >> n >> k;
  l = 1, r = n;
  while (1) {
    if (r - l + 1 <= 4 * k + 4) {
      long long x = l + rand() % (r - l + 1);
      if (!get(x, x)) {
        l = max(l - k, 1ll);
        r = min(n, r + k);
      } else
        break;
    } else {
      long long m = (l + r) / 2;
      if (get(l, m)) {
        l = max(l - k, 1ll);
        r = min(n, m + k);
      } else {
        l = max(m - k + 1, 1ll);
        r = min(r + k, n);
      }
    }
  }
}
