Data Type C# Tutorial

using System;
    class MainClass
    {
        static void Main(string[] args)
        {
            ulong loopCount = 0;
            ulong factorial = 1;
            loopCount = 23;
            for( ulong i = loopCount; i > 0; i-- )
            {
                factorial *= i;
            }
            Console.WriteLine( "{0}! = {1}", loopCount, factorial );
        }
    }