using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        List<Vehicle> vehicles = new List<Vehicle>();

        Vehicle car = new Vehicle();

        vehicles.Add(car);

        Console.WriteLine(vehicles.Count);

    }

}

​

public class Wheel

{

    public int Diameter { get; set; }

    public int Width { get;set; }

    public int Profile { get;set; }

}

​

public class Vehicle

{

    public List<Wheel> Wheels { get; set;}

}

​

public class Bus : Vehicle

{

    public bool PreparedForSchool { get; set; }

}