generate response: I would like to book the train with the shortest travel time, if that narrows it down. I will also need the reference number.. Intent: book_train. Slots: train-bookpeople=3, train-day=sunday, train-departure=peterborough, train-destination=cambridge, train-leaveat=19:15
Response: Train TR3922 is leaving at 19:19 and arriving at 20:09. Booking was successful for 3 tickets, totaling 39.59 GBP. The Reference number is : WF0T26CV .