Update app.py

app.py

@@ -319,7 +319,7 @@ Do not use [ ] or code blocks for math expressions; use math delimiters instead.
         messages.append({"role": "user", "content": f"Solve this math problem step-by-step: {problem_text}"})
         # Create the completion
         completion = client.chat.completions.create(
-            model="deepseek/deepseek-r1-0528:free",
+            model="meta-llama/llama-3.3-70b-instruct:free",
             messages=messages,
             extra_headers={
                 "HTTP-Referer": "https://advancedmathtutor.edu",