#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long int getRand(long long int l, long long int r) {
  uniform_int_distribution<long long int> uid(l, r);
  return uid(rng);
}
bool ask_query(long long int l, long long int r) {
  cout << l << " " << r << "\n";
  cout.flush();
  string res;
  cin >> res;
  if (res == "Yes") {
    if (l == r) {
      exit(0);
    }
    return 1;
  } else if (res == "No") {
    return 0;
  } else {
    exit(0);
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n, k;
  cin >> n >> k;
  if (n == 1) {
    ask_query(1, 1);
  }
  long long int l, r;
  if (ask_query(1, n / 2)) {
    l = 1;
    r = (n / 2) + k;
  } else {
    l = (n / 2) + 1ll - k;
    r = n;
  }
  l = max(1ll, l);
  r = min(n, r);
  while (1) {
    while (r - l + 1ll > 5 * k) {
      long long int mid = (l + r) / 2;
      if (ask_query(l, mid)) {
        l = l - k;
        r = mid + k;
      } else {
        r += k;
        l = mid + 1ll - k;
      }
      l = max(1ll, l);
      r = min(n, r);
    }
    long long int indx = getRand(l, r);
    if (ask_query(indx, indx)) {
      exit(0);
    }
    l -= k;
    r += k;
    l = max(1ll, l);
    r = min(n, r);
  }
}
