generate response: Oh sillly me! I'm leaving from Bishops Stortford. Doesn't matter what time I arrive, just can't leave until 20:45. Intent: find_train. Slots: train-day=saturday, train-departure=bishops stortford, train-destination=cambridge, train-leaveat=20:45
Response: Okay I have a train that departs at 21:29. Shall I book it for you?