generate response: Yes, can you book it for 7 people and give me the reference number?. Intent: book_train. Slots: train-bookpeople=7, train-day=friday, train-departure=cambridge, train-destination=stansted airport, train-leaveat=13:45
Response: Booked! Reference number is FQB8ZKSP . You will pay 70.7 GBP at the station.