#include <bits/stdc++.h>
using namespace std;
inline void prep() {
  cin.tie(0);
  cin.sync_with_stdio(0);
};
const int mod = (int)1e9 + 7;
const int MX = (int)2e5 + 10;
bool ask(long long x, long long y) {
  cout << x << " " << y << '\n' << flush;
  string res;
  cin >> res;
  return res == "Yes";
}
bool guess(long long x) { return ask(x, x); }
int main() {
  prep();
  mt19937 gen;
  gen.seed(chrono::steady_clock::now().time_since_epoch().count() + 10);
  uniform_int_distribution<long long> dis(0, 9e18);
  long long n, k;
  cin >> n >> k;
  long long l = 1, r = n;
  while (l <= r) {
    long long sz = (r - l + 1);
    if (sz <= 64) {
      if (guess(l + (dis(gen) % sz))) return 0;
      l = max(1LL, l - k);
      r = min(n, r + k);
    } else {
      long long mid = (l + r) / 2;
      bool ok = ask(l, mid);
      if (ok) {
        l = max(1LL, l - k);
        r = min(n, mid + k);
      } else {
        l = max(1LL, mid + 1 - k);
        r = min(n, r + k);
      }
    }
  }
  return 0;
}
