generate response: I want to go to London Liverpool Street on Friday.. Intent: find_train. Slots: train-day=friday, train-departure=cambridge, train-destination=london liverpool street, train-leaveat=21:30
Response: TR9557 leaves at 21:59, or, if that is too close to 21:30, TR3138 leaves at 23:59. Do either of those options work for you?