i am planning a trip in cambridge , looking for a train i need to leave on a saturday .
sure , what day will you be traveling ?
{'service': 'train', 'act': 'request', 'slot_name': 'dest', 'value': '?'} {'service': 'train', 'act': 'request', 'slot_name': 'depart', 'value': '?'}
please tell me your destination and departure site so that i can narrow down the options