generate response: I want to make a booking for 4 people. Intent: book_train. Slots: train-bookpeople=4, train-day=sunday, train-departure=london kings cross, train-destination=cambridge, train-leaveat=13:30
Response: You are successfully booked for 4 tickets on Train TR7931. The total fee is 75.52 GBP, payable at the station. Reference number is : E72IOZ6V .