using System;

using System.IO;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static readonly char[] ReservedCharacters = new[] { '"', '!', '*', '\'', '(', ')', ';', ':', '@', '&', '=', '+', '$', '/', '?', '%', ',', '#', '[', ']', ' ' };

    public static void Main()

    {       

         var fileNames = new Dictionary<string, string>

            {

                {"><myFile *%@|?.txt", "myFile.txt"},

                {"myFile.png", "myFile.png"}

            };

            foreach (var fileName in fileNames)

            {

                var cleanedFileName = CleanFileName(fileName.Key);

                if (string.Equals(cleanedFileName, fileName.Value))

                    Console.WriteLine("PASS - '{0}' => '{1}'.", fileName.Key, fileName.Value);

                else

                    Console.WriteLine("FAILED - Expected '{0}' but received '{1}'.", fileName.Value, cleanedFileName);

            }

    }

    public static string CleanFileName(string fileName)

    {

        if (string.IsNullOrEmpty(fileName)) return fileName;

        fileName = Path.GetInvalidFileNameChars().Aggregate(fileName, (current, c) => current.Replace(c.ToString(), string.Empty));

        return ReservedCharacters.Aggregate(fileName, (current, c) => current.Replace(c.ToString(), string.Empty));

    }

}