import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
class Main {
    public static void main(String[] args) {
    class Book{
    Private Stringtitle;
        private boolean isBorrowed;

        publi Book(String title){
            this.title =title;
            this.isBorrowed=false;
        }
        public String getTitle() {return title; }
        public boolean isBorrowed(){return isBorrowed; }
            public void borrow () {isBorrowed = true;}
        }
        class Library {
        private ArrayList<Book>books;
        private int userCount;
        

        public Library() {
            books=new ArrayList<>();
            books.add(new Book("Java programming"));
            books.add(new book("Operating Systems"));
            books.add(new book("Databasa Systems"));
            books.add(new book("Computer Networking"));
            books.add(new book("Cyber Security"));
            userCount = 0;
}
            
    public void viewBooks() {
        System.out.println("\nAvailable Books:");
        for(int i=0;i<books.size(); i++) {
        Book b= books.get(i); 
        String status =b. isBorrowed()? "[Borrowed]" : "";
        System.out.println((i + 1) + "." + b.getTitle () +status);
            
        }     
    }
            
public void addBook(String title) {
books.add(new Book(title));
System.out.println("Book added successfully ! ");
    

}
public void borrowBook(int bookNimber) {
if (bookNumber >=1 && bookNumber <= books.size()){
    Book b=books.get(bookNumber- 1);
if(!b.isBorrowed()) {
b.borrow();
System.out.println("You accessed :" + b.getTitle());
userCount++;  
System.out.println("Invalid book number.");

}
    
}
    
Public void showUsers() {
System.out.println("Number of users who accessed library: " + userCount);
  }
    
}

Public class LibrarySystem {
public static void main(String[] args) {
scanner input = new scanner (System.in);
Library lib = new Library();
    int choice;
    
  do  {
    System.out.println("\n==== LIBRARY MANAGEMENT ====");
    System.out.println("1.open library");
    System.out.println("2.view Books");
    System.out.println("3.Access / Borrow Book");
    System.out.println("4.manage Books (Add Book)";
    Sytem.out.println("5.show Number of Users");
    System.out.println("6.Exit");
    System.out.print("Enter your choice:");
    choice =input.nextInt();
    input.nextLine();

      switch (choice) {

          case 1: 
    System.out.println("library opened successfully!");
              break;
          case 2: lib .viewBooks();
              break;
          case 3:
        System.out.print("Salim: ");
        String name = input.nextLine();
        System.out.println("welcome,"+ Salim + "!");
        System.out.print("3:");
              int num = input.nextInt();
            lib.borrowBook(num);
            input.nextline();
              break;
          case 4: 
            System.out.print("Operating Systems: ");
            String newBook = input.nextLine();
            lib.addBook(newBook);
              break;
          case 5: lib.showUsers();
              break;
          case 6:
        System.out.println("Thanks for using  the library.");
              break;
          default:
        System.out.println("invalid choice.");
            
      }
       
    } while (choice !=6);
    input.close();
}
    }