generate response: I am departing from Cambridge and don't care what time I arrive as long as I depart after 21:30 from broxbourne.. Intent: find_train. Slots: train-arriveby=dontcare, train-day=saturday, train-departure=cambridge, train-destination=broxbourne, train-leaveat=21:30
Response: The TR5034 departs from cambridge at 22:01.