Update app.py

app.py

@@ -21,7 +21,7 @@ DEFAULT_API_URL = "https://agents-course-unit4-scoring.hf.space"
 #model=LiteLLMModel(model_id="deepseek-ai/DeepSeek-Coder-V2-Lite-Base", api_key=os.getenv('HF_API_KEY'))
 #model=LiteLLMModel(model_id="gemini/gemini-2.0-flash-lite", api_key=os.getenv('GEMINI_API_KEY'))
 #model=OpenAIServerModel(model_id="gpt-4o", api_key=os.getenv('OPENAI_API_KEY'))
-model=OpenAIServerModel(model_id="GPT-4.1 nano", api_key=os.getenv('OPENAI_API_KEY'))
+model=OpenAIServerModel(model_id="gpt-3.5-turbo", api_key=os.getenv('OPENAI_API_KEY'))
 #model=LiteLLMModel(model_id="deepseek/deepseek-chat", api_key=os.getenv('DEEPSEEK_API_KEY'))
 
 # Initialize the model