i would like to eat not too pricy or cheap in centre of town .
{'service': 'restaurant', 'act': 'request', 'slot_name': 'food', 'value': '?'} {'service': 'restaurant', 'act': 'inform', 'slot_name': 'choice', 'value': '21'}
there are 21 available restaurant -s . do you want to specify food type ?