generate response: I need to leave london liverpool street and be in cambridge by 21:00.. Intent: find_train. Slots: train-arriveby=21:00, train-day=wednesday, train-departure=london liverpool street, train-destination=cambridge
Response: There are 8 trains that would work on Wednesday. Do you have a departure time in mind? You could leave london as early as 07:39 or as late as 17:39.