#include <bits/stdc++.h>
using namespace std;
long long int n, k;
long long int rand_int(long long int a, long long int b) {
  return rand() % (b - a + 1) + a;
}
int ask(long long int l, long long int r) {
  cout << l + 1 << " " << r + 1 << "\n";
  cout.flush();
  string res;
  cin >> res;
  if (res == "Yes") {
    return 1;
  } else if (res == "No") {
    return 0;
  }
  return -1;
}
int main() {
  ios_base::sync_with_stdio(false);
  srand(time(0));
  cin >> n >> k;
  long long int l = 0;
  long long int r = n - 1;
  while (true) {
    l = max((long long int)0, l - k);
    r = min(n - 1, r + k);
    if (r - l <= 60) {
      long long int check = rand_int(l, r);
      if (ask(check, check)) {
        return 0;
      }
    } else {
      long long int mid = (l + r) / 2;
      if (ask(l, mid)) {
        r = mid;
      } else {
        l = mid + 1;
      }
    }
  }
  return 0;
}
