public class Library {
    private Object[] holdings;
    private int count;

    public Library(int size) {
	if (size < 1) {
	    throw new IllegalArgumentException("invalid capacity");
	}
	holdings = new Object[size];
	count = 0;
    }

    public void add(Object item) {
	for (int i = 0; i < count; i++)
	    if (holdings[i].equals(item))
		return;
	holdings[count] = item;
	count++;
    }

    public String toString() {
	String s = "Library:\n";
	for (int i = 0; i < count; i++)
	    s += holdings[i] + "\n";
	return s;
    }

    public static void main(String[] args) {
	Library lib = new Library(10);
	lib.add(new Book("War and Peace", 1000));
	lib.add(new Book("War and Peace", 1000));
	lib.add(new Video("Pirates of Silicon Valley", 105));
	System.out.println(lib);
    }

}