using System;

​

class Book

{

    public string Title { get; set; } = "";

    public string Author { get; set; } = "";

    public override bool Equals(object? obj)

    {

        if (obj is Book book)

        {

            return Title == book.Title && Author == book.Author;

        }

        return false;

    }

    public override int GetHashCode()

    {

        return Title.GetHashCode() + Author.GetHashCode();

    }

}

​

public class Program

{

    public static void Main()

    {

        var book1 = new Book() { Title = "The Witcher", Author = "Sapkowski" };

        var book2 = new Book() { Title = "Harry Potter", Author = "Rowling" };

        var book3 = new Book() { Title = "Harry Potter", Author = "Rowling" };

        bool book1Equalsbook2 = book1.Equals(book2);

        bool book1Equalsbook3 = book1.Equals(book3);

        Console.WriteLine(book1Equalsbook2);

        Console.WriteLine(book1Equalsbook3);

    }

}