#include <bits/stdc++.h>
using namespace std;
const long long N = 1e6 + 5;
const long long INF = 1e9 + 7;
long long n, k;
bool ask(const long long &l, const long long &r) {
  cout << l << " " << r << endl;
  fflush(stdout);
  string s;
  cin >> s;
  if (l == r && s == "Yes") exit(0);
  return s == "Yes";
}
inline void Find(const long long &l, const long long &r, bool check) {
  bool C = false;
  if (r - l + 1 <= 50) C = true;
  if (C) {
    long long pos = (rand() * rand()) % (r - l + 1) + l;
    ask(pos, pos);
    Find(max(1LL, l - k), min(n, r + k), C | check);
  }
  long long mid = (l + r) >> 1;
  if (ask(l, mid))
    Find(max(1LL, l - k), min(n, mid + k), C | check);
  else
    Find(max(1LL, mid - k), min(n, r + k), C | check);
}
int main() {
  srand(time(NULL));
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> k;
  if (n <= 4500)
    for (long long i = 1; i <= n; i++) ask(i, i);
  Find(1, n, false);
  return 0;
}
