#include <bits/stdc++.h>
const double PI = acos(-1.0);
const long long MOD = 1000000007;
template <class T, class S>
using umap = std::unordered_map<T, S>;
using ll = long long;
using namespace std;
int main() {
  ll n;
  ll p[200010];
  string s;
  cin >> n;
  n %= 10;
  if (n == 3) {
    cout << "bon" << endl;
  } else if (n == 0 || n == 1 || n == 6 || n == 8) {
    cout << "pon" << endl;
  } else {
    cout << "bon" << endl;
  }
  return 0;
}
