diff --git a/oop_basics/book.js b/oop_basics/book.js
new file mode 100644
index 0000000..3f90c88
--- /dev/null
+++ b/oop_basics/book.js
@@ -0,0 +1,49 @@
+export default class Book {
+    constructor(title, author, releaseYear) {
+        this._title = title;
+        this._author = author;
+        this._releaseYear = releaseYear;
+    }
+
+    get title() {
+        return this._title;
+    }
+
+    set title(newTitle) {
+        if (typeof newTitle !== 'string' || newTitle.trim() === '') {
+            throw new Error('Invalid input. Title must be a non-empty string.');
+        }
+        this._title = newTitle;
+    }
+
+    get author() {
+        return this._author;
+    }
+
+    set author(newAuthor) {
+        if (typeof newAuthor !== 'string' || newAuthor.trim() === '') {
+            throw new Error('Invalid input. Author must be a non-empty string.');
+        }
+        this._author = newAuthor;
+    }
+
+    get releaseYear() {
+        return this._releaseYear;
+    }
+
+    set releaseYear(newYear) {
+        if (typeof newYear !== 'number') {
+            console.error('Invalid input. Year must be a number.');
+            return;
+        }
+        this._releaseYear = newYear;
+    }
+
+    printInfo() {
+        console.log(`Title: ${this._title}, Author: ${this._author}, Release Year: ${this._releaseYear}`);
+    }
+
+    static findOldestBook(books) {
+        return books.reduce((oldest, current) => (oldest.releaseYear < current.releaseYear ? oldest : current));
+    }
+}
\ No newline at end of file
diff --git a/oop_basics/eBook.js b/oop_basics/eBook.js
new file mode 100644
index 0000000..ae5091a
--- /dev/null
+++ b/oop_basics/eBook.js
@@ -0,0 +1,28 @@
+import Book from './book.js';
+
+export default class EBook extends Book {
+    constructor(title, author, releaseYear, fileFormat) {
+        super(title, author, releaseYear);
+        this._fileFormat = fileFormat;
+    }
+
+    get fileFormat() {
+        return this._fileFormat;
+    }
+
+    set fileFormat(newFormat) {
+        if (typeof newFormat !== 'string' || newFormat.trim() === '') {
+            throw new Error('Invalid input. File format must be a non-empty string.');
+        }
+        this._fileFormat = newFormat;
+    }
+
+    printInfo() {
+        super.printInfo();
+        console.log(`File Format: ${this._fileFormat}`);
+    }
+
+    static createEBookFromBook(bookInstance, fileFormat) {
+        return new EBook(bookInstance.title, bookInstance.author, bookInstance.releaseYear, fileFormat);
+    }
+}
\ No newline at end of file
diff --git a/oop_basics/task1.js b/oop_basics/task1.js
new file mode 100644
index 0000000..ba302ff
--- /dev/null
+++ b/oop_basics/task1.js
@@ -0,0 +1,21 @@
+import Book from './book.js';
+import EBook from './eBook.js';
+
+const book1 = new Book('Title1', 'Author1', 2000);
+const book2 = new Book('Title2', 'Author2', 2010);
+
+const ebook1 = new EBook('E-Title1', 'E-Author1', 2020, 'PDF');
+const ebook2 = new EBook('E-Title2', 'E-Author2', 2021, 'EPUB');
+
+book1.printInfo();
+book2.printInfo();
+ebook1.printInfo();
+ebook2.printInfo();
+
+const oldestBook = Book.findOldestBook([book1, book2, ebook1, ebook2]);
+console.log('Oldest book:');
+oldestBook.printInfo();
+
+const newEBook = EBook.createEBookFromBook(book2, 'MOBI');
+console.log('New EBook:');
+newEBook.printInfo();
\ No newline at end of file