using System;

public class Program

{

    public static void Main()

    {

        ulong key= 0;

        bool parseResult = ulong.TryParse("90c7a0e64214417c", System.Globalization.NumberStyles.HexNumber, System.Globalization.CultureInfo.InvariantCulture, out key);

        Console.WriteLine(parseResult);

        Console.WriteLine(key);

    }

}