user_turns: <SILENCE> im looking for a cheap restaurant that serves vietnamese food <SILENCE> what is the 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 vietnamese R_location cheap thanh_binh serves vietnamese food in the cheap price range The phone number of thanh_binh is thanh_binh_phone  you are welcome