generate response: I'm going to bishops stortford after work, after 21:15 would work.. Intent: find_train. Slots: train-day=saturday, train-departure=cambridge, train-destination=bishops stortford, train-leaveat=21:15
Response: I have two trains that leave after that time. One departs at 21:29 and the other departs at 23:29. Which would you prefer?