fixed casting

app.py

@@ -47,7 +47,7 @@ def generate_reply(user_input, chat_history):
 def generate_quiz(subject, num_questions, chat_history):
     """Generate a history quiz with multiple-choice questions and append it to the chat."""
     try:
-        num_questions = int(num_questions)  
+        num_questions = str(num_questions)  
         prompt = f"Generate {num_questions} multiple-choice history questions about {subject}. "
         prompt += "For each question, provide the question text, four options labeled A, B, C, and D, and at the end of all questions, list the correct answers in the format: 'Correct Answers: X, Y, Z, ...'."