generate response: Can I get the one that arrives closest to 13:45? Can you book that for 6 seats and give me the reference number?. Intent: book_train. Slots: train-arriveby=13:45, train-bookpeople=6, train-day=tuesday, train-departure=cambridge, train-destination=stansted airport
Response: I have one train leaving cambridge at 12:40 and arriving at stansted airport at 13:08. Shall I book it for you?