generate response: I need one on Friday heading to Ely. I need to leave after 19:30.. Intent: find_train. Slots: train-day=friday, train-departure=cambridge, train-destination=ely, train-leaveat=19:30
Response: The train closest to your desired time is TR6053 which departs Cambridge at 19:50 and arrives in Ely at 20:07. Would you like to book a ticket?