Update app.py

app.py

@@ -108,7 +108,7 @@ retriever = db.as_retriever(
 # )
 
 llm = ChatOpenAI(
-    model="Qwen/Qwen2.5-72B-Instruct",
+    model="meta-llama/Llama-3.3-70B-Instruct",
     temperature=0,
     max_tokens=None,
     timeout=None,