class Book
{
	public String title;
	public String author;

	public Book(String t, String a)
	{
		title = t;
		author = a;	
	}

	public String toString()
	{
		return title + " " + author;
	}

	public boolean equals(Book book)
	{
		return (book instanceof Book) && ((Book)book).title == title && ((Book)book).author == author;
	}
}

class Set
{
	private int capacity;
	Book[] books;
	private int i;	

	public Set(int c)
	{
		capacity = c;
		books = new Book[capacity];
	}

	public boolean addBook(Book book)
	{
		if(i==0)
		{
			books[i] = book;
			i++;
			return true;
		}
	

	if(i==capacity)
	{	
		return false;
	}

	for(i=1 ; i<=capacity ; i++)
	{
		if((books[i].equals(book))==true)
		{
			return false;
		}
	}

	if(books[i].equals(book)==false)
	{
		books[i] = book;
		i++;
	}	
	return true;		
   }
}

class setMain
{
	public static void main (String []args)
	{
		Set s1 = new Set(3);
		Book b1 = new Book("Aa","Bb");
		Book b2 = new Book("Cc","Dd");
		Book b3 = new Book("Aa","Bb");

		System.out.println(b1);
		System.out.println(b2);
		System.out.println(b3);

		s1.addBook(b1);
		s1.addBook(b2);
		s1.addBook(b3);
	}	
}