#include <bits/stdc++.h>
int main(void) {
  int N;
  scanf("%d", &N);
  N = N % 10;
  if (N == 3)
    printf("bon");
  else if (N == 0 || N == 1 || N == 6 || N == 8)
    printf("pon");
  else
    printf("bon");
  return 0;
}
