using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        String text = " semi-automatic .22 14'' ?KJlk  d()d ds 100% ";

        text = text

                .ToLower();

        text = Regex.Replace(text, "[\\.\\?!:-]", " ")

                .Trim();

        text = Regex.Replace(text, "  ", " ");

        text = Regex.Replace(text, "[^A-Za-z0-9 ]", "");

        String[] words = text.Split(' ');

        Console.WriteLine(string.Join(", ", words));

    }

}