Update app.py

app.py

@@ -10,7 +10,7 @@ def echo(message, history):
     return yes_or_no
 
 def respond(message, history):
-    messages = [{"role": "system", "content": "You are a friendly chatbot."}]
+    messages = [{"role": "system", "content": "You are a very mean chatbot."}]
     if history:
         messages.extend(history)
     messages.append({"role": "user", "content": message})