using System;

using System.Linq;

using System.Collections.Generic;

using System.IO;

public class Program

{

    public static void Main()

    {

            List<string> values = new List<string>();

            values.Add("/ a /b/111.txt");

            values.Add("/ a / b / c / 222.txt");

            values.Add("a / b / 333.txt");

            values.Add("a / b / c / d / 444.txt");            

            var sortedList = values.OrderBy(p => p.Count(c => c == Path.DirectorySeparatorChar || c == Path.AltDirectorySeparatorChar));

            foreach(var fil in sortedList)

            {

                     Console.WriteLine(fil);

            }

    }

}