#include <stdio.h>

 int main(){
    int n;
    scanf("%d", &n)

    switch(n%10){
        case 2:
        case 4:
        case 5:
        case 7:
        case 9:
           puts("bon");
        break;
         case 0:
         case 1:
         case 6:
         case 8:
           puts("pon");
           break;
         case 3:
            puts("bon");
            break;
    }
    return 0;
 }