using System;
using System.Linq;

namespace P01.Valid_Username
{
    class Program
    {
        static void Main()
        {
           string[] input = Console.ReadLine().Split(", ",StringSplitOptions.None).ToArray();

            foreach (var username in input)
            {
                if (ValidUsername(username))
                {
                    Console.WriteLine(username);
                }
            }


        }

        static bool ValidUsername(string username)
        {
            bool isValid = true;

            if (username.Length<3||username.Length>16)
            {
                return false;
            }

            for (int i = 0; i < username.Length; i++)
            {
                char currCh = username[i];

                if (char.IsLetterOrDigit(currCh)||currCh=='-'|| currCh=='_')
                {
                    isValid = false;
                    break;
                }

            }

            return isValid;
        }
    }
}