using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main(string[] args)
    {
        Regex pattern = new Regex(@"(?<=^|,\s)([\w\-]{3,16})(?=$|,\s)");
        string input = Console.ReadLine();
        MatchCollection matches = pattern.Matches(input);

        foreach (var match in matches)
        {
            Console.WriteLine(match);
        }
    }
}