using System;

using System.Runtime.ExceptionServices;

​

class Program

{

    public static void Main(string[] args)

    {

        var lastThenDecode = Uri.UnescapeDataString(new Uri("http://www.ww.ww/backup/object-audit%2F2012%2F11%2F15%2F637557347536065816%2F18446744073709551506%2FAddDocument%2F18446744073709551406.json").Segments[^1]);

        Console.WriteLine(lastThenDecode);

        // This...

        var decodeThenLast = new Uri(Uri.UnescapeDataString("http://www.ww.ww/backup/object-audit%2F2012%2F11%2F15%2F637557347536065816%2F18446744073709551506%2FAddDocument%2F18446744073709551406.json")).Segments[^1];

        Console.WriteLine(decodeThenLast);

    }

}