generate response: Could you book 2 tickets on that train please? Also, what is the reference number?. Intent: book_train. Slots: train-arriveby=08:45, train-bookpeople=2, train-day=thursday, train-departure=london liverpool street, train-destination=cambridge
Response: Alright, you have booked two tickets on TR3839, leaving at 05:39. Your reference number is XDXE55LY .