Add unknown messages

app.py

@@ -47,7 +47,8 @@ def postprocess(text):
 
 # get answer from LLM with prompt input
 def answer(text,context=""):
-  text = f"{context}\n{text}\n谜底："
+  text = f"{context}\n{text}\n谜底：\n如果不知道，请说不知道。"
+    
   text = text.strip()
 
   print(text)