using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var a = new A();

        Console.WriteLine(a.Number);

    }

}

​

class A

{

    int _number;

    public int Number

    {

        get

        {

            return this._number;

        }

        set

        {

            this._number = value;

        }

    }

}