#include <bits/stdc++.h>
using namespace std;
long long lft, rgt, k, n, rd;
string s;
int main() {
  cin >> n >> k;
  lft = 1, rgt = n;
  for (;;) {
    while (rgt - lft + 1 > 8 * k) {
      long long mid = (rgt + lft) / 2;
      cout << lft << ' ' << mid << '\n';
      fflush(stdout);
      cin >> s;
      if ((s == "Yes") && (lft == mid)) return 0;
      if (s == "Yes")
        lft = max(lft - k, 1LL), rgt = min(n, mid + k);
      else
        lft = max(mid + 1 - k, 1LL), rgt = min(rgt + k, n);
    }
    long long x = (rd % (rgt - lft + 1)) + lft;
    rd++;
    cout << x << ' ' << x << '\n';
    fflush(stdout);
    cin >> s;
    if (s == "Yes") return 0;
    lft = max(lft - k, 1LL);
    rgt = min(rgt + k, n);
  }
  return 0;
}
