generate response: Let's go with the 10:11 train. I'd like to book for 4 people and will need a reference number, please.. Intent: book_train. Slots: train-bookpeople=4, train-day=sunday, train-departure=cambridge, train-destination=kings lynn, train-leaveat=09:30
Response: I have booked the train from Cambridge to Kings Lynn for Sunday leaving at 10:11 and arriving by 10:58. Reference # 4LPYRWCU .