using System;

public class Program

{

    public static void Main()

    {

          List<int> grades = new List<int>();

​

            Console.WriteLine("[0] - add");

            Console.WriteLine("[1] - delete");

            Console.WriteLine("[2] - insert");

            Console.WriteLine("[3] - get avrage of grades");

            Console.WriteLine("[4] - Exit program");

​

            int function = int.Parse(Console.ReadLine());

            switch (function)

            {

                case 1:

                    grades.Add(Console.ReadLine());

                    break;

​

                case 2:

​

​

                default:

            }

    }

}