generate response: That sounds good. What is the travel time for that train?. Intent: find_train. Slots: train-arriveby=18:10, train-day=thursday, train-departure=cambridge, train-destination=stevenage, train-leaveat=17:21
Response: TR4765 seems to be a better match for what you're looking for, it arrives by 18:10 and total travel time is 49 minutes. Would you like to book a ticket?