user_turns: <SILENCE> afghan afghan food vietnamese food any of town no yes vietnamese anywhere <SILENCE> is it cheap <SILENCE> price range phone number thank you thank you 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 ? What kind of food would you like? I'm sorry but there is no restaurant serving afghan food I'm sorry but there is no vietnamese restaurant in the centre of town Did you say you are looking for a restaurant in the centre of town? You are looking for a vietnamese restaurant right? I'm sorry but there is no vietnamese restaurant in the centre of town api_call vietnamese R_location R_price thanh_binh serves vietnamese food api_call vietnamese R_location cheap thanh_binh is a great restaurant thanh_binh is in the cheap price range The phone number of thanh_binh is thanh_binh_phone thanh_binh is a great restaurant  you are welcome