#include <bits/stdc++.h>
using namespace std;
bool ask(long long l, long long r) {
  cout << l << " " << r << endl;
  string s;
  cin >> s;
  if (s == "Yes") {
    if (l == r) exit(0);
    return 1;
  }
  return 0;
}
long long l, r, n, k;
void boom() {
  long long mid = (l + r) / 2;
  if (ask(l, mid))
    r = mid;
  else
    l = mid + 1;
  r = min(n, r + k);
  l = max(1ll, l - k);
}
int main() {
  srand(time(0));
  cin >> n >> k;
  l = 1, r = n;
  while (r - l + 1 > 4 * k) {
    boom();
  }
  while (1) {
    long long d = rand() % (r - l + 1);
    ask(l + d, l + d);
    r = min(n, r + k);
    l = max(1ll, l - k);
    while (r - l + 1 > 4 * k) {
      boom();
    }
  }
}
