generate response: Yes please book the closest one to my preferred time for 7 people. I would also appreciate a reference number.. Intent: book_train. Slots: train-bookpeople=7, train-day=sunday, train-departure=cambridge, train-destination=broxbourne, train-leaveat=13:00
Response: Ok. I booked 7 tickets on TR4414. Your reference number is 4C0J1MKO .