generate response: I need a travel time and train ID for the last train to arrive at stansted airport before 13:15.. Intent: find_train. Slots: train-arriveby=13:15, train-day=wednesday, train-departure=cambridge, train-destination=stansted airport
Response: The train ID is TR0644. It leaves at 12:40 and arrives at 13:08 for a total travel time of 28 minutes.