#include <bits/stdc++.h>
using namespace std;
signed main() {
  string n;
  cin >> n;
  n = n[0] == '3'                                                ? "bon"
      : n[0] == '0' || n[0] == '1' || n[0] == '6' || n[0] == '8' ? "pon"
                                                                 : "bon";
  cout << n;
}
