#include <bits/stdc++.h>
using namespace std;
bool ok(long long l, long long r) {
  cout << l << " " << r << endl;
  string s;
  cin >> s;
  if (s == "Bad") {
    exit(1);
  }
  if (s == "Yes" && l == r) exit(0);
  return s == "Yes";
}
int32_t main() {
  mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
  long long n, k;
  cin >> n >> k;
  long long l = 1, r = n;
  while (l < r) {
    if (r - l + 1 > 40) {
      long long m = (l + r) / 2;
      if (ok(l, m)) {
        r = m;
      } else {
        l = m + 1;
      }
      l = max(1ll, l - k);
      r = min(n, r + k);
    } else {
      long long x = l + rng() % (r - l + 1);
      if (!ok(x, x)) {
        l = max(1ll, l - k);
        r = min(n, r + k);
      } else {
        exit(0);
      }
    }
  }
  ok(l, r);
}
