Нужно реализовать интерфейс IComparable в каждом из наследуемых классов - C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace OOP_Lab_11
{
    abstract class Software
    {
        public string Name;
        public string Manufacturer;
        public virtual void ShowInfo()
        {
            Console.WriteLine("Name: " + Name);
            Console.WriteLine("Manufacturer: " + Manufacturer);
        }
        public abstract void Search(string n);
    }
    class Freeware : Software
    {
        public Freeware(string Name, string Manufacturer)
        {
            this.Name = Name;
            this.Manufacturer = Manufacturer;
        }
        public override void ShowInfo()
        {
            Console.WriteLine("Freeware: ");
            base.ShowInfo();
        }
        public override void Search(string n)
        {
        }
    }
    class ShareWare : Software
    {
        protected string TimeOfFreeUsing;
        protected string Date;
        public ShareWare(string Name, string Manufacturer, string Date, string TimeOfFreeUsing)
        {
            this.Name = Name;
            this.Manufacturer = Manufacturer;
            this.TimeOfFreeUsing = TimeOfFreeUsing;
            this.Date = Date;
        }
        public override void ShowInfo()
        {
            Console.WriteLine();
            Console.WriteLine("ShareWare: ");
            base.ShowInfo();
            Console.WriteLine("Date of installing: " + Date);
            Console.WriteLine("Time of free using: " + TimeOfFreeUsing);
        }
        public override void Search(string n)
        {
            if (this is ShareWare) if (n == this.Date) this.ShowInfo();
        }
    }
    class Commercial : Software
    {
        public int Price;
        protected string Date;
        protected string TimeOfUsing;
        public Commercial(string Name, string Manufacturer, int Price, string Date, string TimeOfUsing)
        {
            this.Name = Name;
            this.Manufacturer = Manufacturer;
            this.Price = Price;
            this.TimeOfUsing = TimeOfUsing;
            this.Date = Date;
        }
        public override void ShowInfo()
        {
            Console.WriteLine();
            Console.WriteLine("Commercial: ");
            base.ShowInfo();
            Console.WriteLine("Price: " + Price);
            Console.WriteLine("Date of installing: " +Date);
            Console.WriteLine("Time of using: " +TimeOfUsing);
        }
        public override void Search(string n)
        {
            if (this is Commercial) if (n == this.Date) this.ShowInfo();
        }
    }
    class Program
    {
        private static List<Freeware> FreewareCollection;
        private static List<ShareWare> SharewareCollection;
        private static List<Commercial> CommercialCollection;
        static void Main(string[] args)
        {
            FreewareCollection = new List<Freeware>();
            SharewareCollection = new List<ShareWare>();
            CommercialCollection = new List<Commercial>();
            Console.WriteLine("Enter the number of list elements");
            int n = Convert.ToInt16(Console.ReadLine());
            for (int i = 0; i < n; i++)
            {
                Console.WriteLine("Freeware: ");
                Console.Write("Name: ");
                string FrwNm = Console.ReadLine();
                Console.Write("Manufacturer: ");
                string FrwMnf = Console.ReadLine();
                Freeware Frw = new Freeware(FrwNm, FrwMnf);
                FreewareCollection.Add(Frw);
                /*-----------------------------------------*/
                Console.WriteLine("ShareWare: ");
                Console.WriteLine("Name: ");
                string ShrwNm = Console.ReadLine();
                Console.WriteLine("Manufacturer: ");
                string ShrwMnf = Console.ReadLine();
                Console.WriteLine("Date of installing: ");
                string ShrwDateOf = Console.ReadLine();
                Console.WriteLine("Time of free using: ");
                string ShrwTmOf = Console.ReadLine();
                ShareWare Shrw = new ShareWare(ShrwNm, ShrwMnf, ShrwDateOf, ShrwTmOf);
                SharewareCollection.Add(Shrw);
                /*-----------------------------------------*/
                Console.WriteLine("Commercial: ");
                Console.WriteLine("Name: ");
                string ComNm = Console.ReadLine();
                Console.WriteLine("Manufacturer: ");
                string ComMnf = Console.ReadLine();
                Console.WriteLine("Price: ");
                int  ComPrice = Convert.ToInt16(Console.ReadLine());
                Console.WriteLine("Date of installing: ");
                string ComDateOf = Console.ReadLine();
                Console.WriteLine("Time of Using: ");
                string ComTimeOf = Console.ReadLine();
                Commercial Comm = new Commercial(ComNm, ComMnf, ComPrice, ComDateOf, ComTimeOf);
                CommercialCollection.Add(Comm);
                /*-----------------------------------------*/
            }
            Console.WriteLine("Collection output");
            for (int i = 0; i < n; i++)
            {
                FreewareCollection[i].ShowInfo();
                SharewareCollection[i].ShowInfo();
                CommercialCollection[i].ShowInfo();
            }
            CommercialCollection.Sort();
            Console.WriteLine("For exit press enter");
            Console.ReadLine();
        }
    }
}