#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 10;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long n, k;
bool ask(long long l, long long r) {
  cout << l << " " << r << endl;
  string ret;
  cin >> ret;
  if (ret == "Bad") exit(0);
  if (ret == "Yes" and l == r) exit(0);
  return ret == "Yes";
}
int main() {
  ios_base::sync_with_stdio(false);
  srand(time(NULL));
  cin >> n >> k;
  long long lo = 1, hi = n;
  while (true) {
    long long len = hi - lo + 1;
    long long mid = (hi + lo) >> 1;
    if (len > 4 * k + 3) {
      if (ask(lo, mid))
        hi = mid;
      else
        lo = mid + 1;
    } else {
      long long x = rng() % len;
      if (ask(lo + x, lo + x)) throw;
    }
    hi = min(hi + k, n);
    lo = max(lo - k, 1ll);
  }
}
