#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, k;
  cin >> n >> k;
  long long l = 1, r = n;
  string ans;
  srand(time(NULL));
  while (1) {
    while ((r - l) > 60) {
      long long mid = (l + r) >> 1;
      cout << l << ' ' << mid << endl;
      cin >> ans;
      if (ans == "Bad") exit(0);
      if (ans == "Yes") {
        l = max(1LL, l - k);
        r = min(mid + k, n);
      } else {
        l = max(1LL, mid - k);
        r = min(r + k, n);
      }
    }
    long long pos = l + rand() % (r - l + 1LL);
    cout << pos << ' ' << pos << endl;
    cin >> ans;
    if (ans == "Bad") exit(0);
    if (ans == "Yes")
      exit(0);
    else
      l = max(1LL, l - k), r = min(r + k, n);
  }
  return 0;
}
