using System;

public class klasa1

{

}   

​

public class Students

{

    public string Name {get;set;}

    public string Surname {get;set;}

    public int Marks {get;set;}

}   

public class Student1 : Students //child class

{

    //public Tyre Tyre {get;set;}

    //public int NumberOfTyres {get;set;}

    public Student1 ()

    {

        Grades = new Grades(5); //contractor 

        NumberOfGrades = 2;

    }

}

​

​

public class Grades

{

    public int NumberOfGrades {get;set;}

    public Grades (int numberofGrades)

    {

        NumberofGrades = numberofGrades;

    }

}

​

public class Program

{

    public static void Main()

    {

        //Car car = new Car(); //object creation

        //Bicycle bicycle = new Bicycle();

        //Motorbike motorbike = new Motorbike();

        //Console.WriteLine(car.Tyre.Size.ToString());

        //Console.WriteLine(bicycle.Tyre.Size.ToString());

        //Console.WriteLine(motorbike.Tyre.Size.ToString());

        //car.ShowNumberOfTyres();

        //bicycle.ShowNumberOfTyres();

    }

}