#include <bits/stdc++.h>
using namespace std;
const double EPS = 1e-9;
signed main() {
  ios::sync_with_stdio(false);
  cout.tie(0);
  cout.precision(20);
  string n;
  cin >> n;
  if (n[n.length() - 1] == '3') {
    cout << "bon" << endl;
  } else if (n[n.length() - 1] == '0' || n[n.length() - 1] == '1' ||
             n[n.length() - 1] == '6' || n[n.length() - 1] == '8') {
    cout << "pon" << endl;
  } else {
    cout << "bon" << endl;
  }
  return 0;
}
