Update app.py

app.py

@@ -638,7 +638,7 @@ Format your response with clear headers and bullet points."""
 
         # Call OpenAI API
         response = openai.chat.completions.create(
-            model="gpt-o1-preview",  # Using o1-preview now
+            model="o1-preview",  # Using o1-preview now
             messages=[
                 {"role": "system", "content": "You are an expert mathematics professor grading student solutions."},
                 {"role": "user", "content": verification_prompt}