#include <bits/stdc++.h>
using namespace std;
long long n, k, l, r;
string reply;
bool lol = 0;
void f() {
  if (r - l > 4 * k + 1) {
    long long sr = (r + l) / 2;
    cout << l << " " << sr << endl;
    cin >> reply;
    if (reply == "Yes")
      r = sr;
    else
      l = sr + 1;
  } else {
    long long kek = rand() % (r - l + 1);
    cout << l + kek << " " << l + kek << endl;
    cin >> reply;
    if (reply == "Yes") lol = 1;
  }
  r = min(r + k, n);
  l = max((long long)1, l - k);
}
int main() {
  srand(time(0));
  ios_base::sync_with_stdio(0);
  cin >> n >> k;
  r = n;
  l = 1;
  while (!lol) {
    f();
  }
  return 0;
}
