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

namespace BookManager
{
    class Program
    {
        static void Main(string[] args)
        {
            Book book1 = new Book("Crazy English", 100, BookType.English);
            Book book2 = new Book("365夜", 100, BookType.Story);
            Book book3 = new Book("設計模式", 100, BookType.Computer);
            POS pos = new POS();
            IDiscount id1 = new EnglishDiscount();
            IDiscount id2 = new StoryDiscount();
            IDiscount id3 = new ComputerDiscount();
            Console.WriteLine(pos.Scan(book1,id1));
            Console.WriteLine(pos.Scan(book2, id2));
            Console.WriteLine(pos.Scan(book3,id3));
        }
    }
}