using System;
using System.Linq;
using System.Collections.Generic;

static class NagataKanaIsAGenius {
    public static void Main() {
        String s=Console.ReadLine();
        int n=s.Length;
        for(int i=0;i<n;i++){
            if(i!=0&&(n-i)%3==0){
                Console.Write(',');
            }
            Console.Write(s[i]);
        }
        Console.WriteLine("");
    }
}