generate response: Yes choose the arrival time closest to 13:15 and book that train for 5 people. Then give me the reference number. Intent: book_train. Slots: train-arriveby=13:15, train-bookpeople=5, train-day=saturday, train-departure=birmingham new street, train-destination=cambridge
Response: Okay, you are booked and reference number is QSA8VDXW