i need a train to cambridge and i need it to leave after 12:45 .
{'service': 'train', 'act': 'inform', 'slot_name': 'choice', 'value': '833'} {'service': 'train', 'act': 'request', 'slot_name': 'depart', 'value': '?'} {'service': 'train', 'act': 'request', 'slot_name': 'day', 'value': '?'}
there are 833 trains that meet your needs . would you like to narrow it down by departure station and and or day of travel ?