Implement IComparer Interface in C#

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace ConsoleApplication1
{



    public class comstude : IComparer<student>
    {

        public int Compare(student x, student y)
        {
            return x.avrage.CompareTo(y.avrage);
        }

    }

    public class student
    {
        public string name;
        public double avrage;
        public student(string name1, double av)
        {
            this.name = name1;
            this.avrage = av;
        }


        public static List<student> getstudentlist()
        {
            List<student> templist = new List<student>();

            templist.Add(new student("esa", 10));
            templist.Add(new student("reza", 20));
            templist.Add(new student("reza1", 17.50));
            templist.Add(new student("reza2", 16));
            templist.Add(new student("reza3", 19));
            templist.Add(new student("reza4", 7));
            return templist;
        }


        public override string ToString()
        {
            return string.Format("name is : {0}\t and averg is\t {1}", name, avrage);
        }

    }
    class Program
    {
        static void Main(string[] args)
        {

            List<student> list = student.getstudentlist();
            list.Sort(new comstude());

            foreach (student var in list)
            {
                Console.WriteLine(var);
            }
            Console.ReadKey();
        }
    }


}