using System;

using System.Collections.Generic;

using System.Linq;

using  System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        List<string> lstFiles = new List<string>(){ "1.pdf",

                                                   "2.pdf",

"99.pdf",

"143.pdf",

"1000.txt",

"999.txt",

                                                   "somename - 110.txt"};

        lstFiles = lstFiles.OrderByDescending(x=> int.Parse(Regex.Replace(x,"[^0-9]+","0"))).ToList<string>();

        foreach(string z in lstFiles)

        {

            Console.WriteLine(z);

        }

    }

}