using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var aa = new Vector(new List<double>(){1,2,3,4});

        Console.WriteLine(aa.dimension());

        var bb = new Vector(new List<double>(){1,2,3});

        Console.WriteLine(bb.dimension());

        var cc = new Vector(new List<double>(){1,2});

        Console.WriteLine(cc.dimension());

    }

    public class Vector

    {

        private List<double> _something;

        public Vector()

        {

        }

        public Vector(List<double> aa)

        {

            _something = aa;

        }

        public int dimension()

        {

            return _something.Count;

        }

    }

}