generate response: How long is the travel time, and what is the price for that train please?. Intent: find_train. Slots: train-day=saturday, train-departure=london liverpool street, train-destination=cambridge, train-leaveat=19:30
Response: Sure, the travel time is 88 minutes, and the price is 13.28 pounds. Would you like to book it, if so how many riders will there be?