#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 2e5 + 5;
ll n, k;
string str;
int main() {
  srand(time(0));
  cin >> n >> k;
  ll l = 1, r = n;
  if (n == 1) {
    cout << 1 << ' ' << 1 << endl;
    cin >> str;
    return 0;
  }
  while (true) {
    while ((r - l + 1) > 50) {
      ll md = (l + r) >> 1;
      cout << l << ' ' << md << endl;
      cin >> str;
      if (str == "Yes") {
        r = md + k;
        l -= k;
      } else {
        l = (md + 1) - k;
        r = r + k;
      }
      r = min(r, n);
      l = max(l, 1ll);
    }
    int x = rand() % (r - l + 1);
    cout << l + x << ' ' << l + x << '\n';
    cin >> str;
    if (str == "Yes") {
      return 0;
    }
    l -= k;
    r += k;
    r = min(r, n);
    l = max(l, 1ll);
  }
  return 0;
}
