public class AbstractBook
{
	public static void main(String args[])
	{
		ComputerBook NewBook=new ComputerBook("Java程序設計","宋波",360);
		System.out.println(NewBook.ShowBook());
	}
}
abstract class Book
{
	String Title;
	String Author;
	int Pages;
	abstract String ShowBook();
}
class ComputerBook extends Book
{
	ComputerBook(String title,String author,int pages)
	{
		Title=title;
		Author=author;
		Pages=pages;
	}
	String ShowBook()
	{
		return("Title: "+Title+" Author: "+Author+" Pages: "+Pages);
	}
}