using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _12GenerateRectangles
{
    class GenerateRectangle
    {
        static void Main(string[] args)
        {
            char[] separators = ".,:;()[]\"'\\/!? ".ToArray();

            List<string> words = Console.ReadLine().ToLower().Split(separators).ToList();

            var shortWords = words.Where(x => x.Length < 5).Where(w => w != "");

            var ordered = shortWords.OrderBy(x => x).Distinct();

            Console.WriteLine(string.Join(", ", ordered));
        }
    }
}