using System;

using System.Threading;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Xml;

using System.Data;

using System.Data.DataSetExtensions;

using System.Text.RegularExpressions;

public class Program

{

    public class X 

    {

        public int Number {get; private set;}

        internal X()

        {

            Number = 5;

        }

        public X(string s)

        {

        }

    }

​

    public static void Main()

    {

        var x0 = new X("test");

        Console.WriteLine(x0.Number);

    }

}