using System;
using System.Globalization;
                    
public class Program
{
    public static void Main()
    {
        var idn = new IdnMapping();
        var url = "xn--ssd-7b7fj34n.com";
        var punyCode = idn.GetAscii(url);
        var url2 = idn.GetUnicode(punyCode);
        Console.WriteLine(url2); // result is ssd換装.com
    }
}