using System;

public class Hello
{
    static void Main()
    {
        var s = Console.ReadLine().Trim();
        if (s.Length <= 3) { Console.WriteLine(s); goto exit; }
        var a = s.Length % 3;
        if (a != 0 ) Console.Write(s.Substring(0, a) + ",");
        put3N(s.Substring(a));
        exit:;
    }
    static void put3N(string s)
    {
        var sL = s.Length;
        for (int i = 0; i < sL; i++)
        {
            Console.Write(s[i]);
            if (i % 3 == 2 && i != sL - 1) Console.Write(',');
        }
        Console.WriteLine();
    }
}