using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        var customer=new Customer();

        customer.Id=1;

        customer.Name="Arti";

        //var order=new Order();

        customer.Orders.Add(new Order());

        customer.Orders.Add(new Order());

        customer.Promote();

        Console.WriteLine(customer.Orders.Count);

        Console.WriteLine(customer.Name);

        //Console.WriteLine("Hello World");

    }

}

public class Customer

{

    public string Name;

    public int Id;

    public readonly List<Order> Orders=new List<Order>();

    public Customer()

    {

    }

    public Customer(int id)

    {

    this.Id=id;

    }

    public Customer(int id,string name):this(id)

    {

        //this.Id=id;

        this.Name=name;

    }

    public void Promote()

    {

        //[]Orders=new List<Order>();

    }

}

public class Order

{

}

​