user_turns: <SILENCE> i want a cheap restaurant that serves european food <SILENCE> how about vietnamese food <SILENCE> whats their phone number thank you good bye
system_turns: Hello , welcome to the Cambridge restaurant system . You can ask for restaurants by area , price range or food type . How may I help you ? api_call european R_location cheap Sorry there is no european restaurant in the cheap price range api_call vietnamese R_location cheap thanh_binh is a great restaurant serving vietnamese food and it is in the cheap price range The phone number of thanh_binh is thanh_binh_phone  you are welcome