import java.util.ArrayList; // import the ArrayList class
import java.util.Date;

public class Book {
    private int id;
    private String title;
    static int count = 0;
    private int yearmade;
    
    public Book(int id, String title, int yearmade) {
        this.id = id;
        this.title = title;
        count++;
        this.yearmade = yearmade;
    }

public int getYear() {
    return yearmade;
}


public void BooktoString() {
    System.out.println("The title of the book is " + this.title);
}

public static int getCount() {
    return count;
}

public static int checkouts() {
    return count/20;
}

public static void main(String[] args) {
    ArrayList<Book> books = new ArrayList<Book>(); // Create an ArrayList object
    Book book1 = new Book(3, "Harry Potter and the Prisoner of Azkaban", 2019);
    Book book2 = new Book(2, "Harry Potter and the Chamber of Secrets", 2020);
    books.add(book1);
    books.add(book2);
    book1.BooktoString();
    book2.BooktoString();
    System.out.println("the num of books is " + Book.getCount());
    
}
}
Book.main(null);

public class Novel extends Book {
    private String author;
    private int i;

    public Novel(int id, String title, int yearmade){
        super(id, title, yearmade);
    }
    
    public void setAuthor(String newauthor) {
        this.author = newAuthor;
    }
    public String getAuthor() {
        return author;
    }

    public int shelflifeNovel() {
        z = 2040 - this.getYear();
        return z - z * this.checkouts();
    }
    public static void main(String[] args) {
        Novel novel1 = new Novel(1, "Don Quixote", 2020);
        int a = novel1.shelflife();
        System.out.println("The shelf life of the novel is " + a);
    }
}
Novel.main(null);

public class Textbook extends Book {
    private String company;
    private int i;

    public Textbook(int id, String title, int yearmade){
        super(id, title, yearmade);
    }
    
    public int shelflifeTextbook() {
        return 2040 - this.getYear();
    }
    public static void main(String[] args) {
        Textbook textbook1 = new Textbook(1, "McGrawHill", 2020);
        int a = textbook1.shelflifeTextbook();
        System.out.println("The shelf life of the textbook is " + a);
    }
}
Textbook.main(null);
The title of the book is Harry Potter and the Prisoner of Azkaban
The title of the book is Harry Potter and the Chamber of Secrets
the num of books is 26
|   
|   
|   public class Novel extends Book {
|       private String author;
|       private int i;
|   
|       public Novel(int id, String title, int yearmade){
|           super(id, title, yearmade);
|       }
|       
|       public void setAuthor(String newauthor) {
|           this.author = newAuthor;
|       }
|       public String getAuthor() {
|           return author;
|       }
|   
|       public int shelflifeNovel() {
|           z = 2040 - this.getYear();
|           return z - z * this.checkouts();
|       }
|       public static void main(String[] args) {
|           Novel novel1 = new Novel(1, "Don Quixote", 2020);
|           int a = novel1.shelflife();
|           System.out.println("The shelf life of the novel is " + a);
|       }
|   }
Unresolved dependencies:
   - variable newAuthor
   - variable z
   - method shelflife()