diff --git a/Start/Ch 1/class_start.py b/Start/Ch 1/class_start.py
index 2c824f9..6b7a609 100644
--- a/Start/Ch 1/class_start.py	
+++ b/Start/Ch 1/class_start.py	
@@ -4,26 +4,34 @@
 
 class Book:
     # TODO: Properties defined at the class level are shared by all instances
+BOOK_TYPES= ("HARDCOVER", "PAPERBACK", "EBOOK")
 
     # TODO: double-underscore properties are hidden from other classes
 
     # TODO: create a class method
-
+@classmethod 
+def get_book_types(cls): 
+     return cls.BOOK_TYPES
     # TODO: create a static method
 
     # instance methods receive a specific object instance as an argument
     # and operate on data specific to that object instance
     def set_title(self, newtitle):
         self.title = newtitle
+        if(not booktype in Book.BOOK_TYPES): 
+            raise ValueError(f"{booktype} is not a valid book type") 
+        else: 
+            self.booktype= booktype 
+            
 
-    def __init__(self, title):
+    def __init__(self, title, booktype):
         self.title = title
 
 
 # TODO: access the class attribute
-
+print("Book types: ", Book.get_book_types())
 
 # TODO: Create some book instances
-
-
+b1= Book("Title1", "HARDCOVER")
+b2= Book("Title1", "COMIC")
 # TODO: Use the static method to access a singleton object