generate response: Yes please can you book seats for 4 people and give me the reference number?. Intent: book_train. Slots: train-arriveby=12:43, train-bookpeople=4, train-day=wednesday, train-departure=stevenage, train-destination=cambridge, train-leaveat=11:54
Response: Your booking was completed and the total fee is 51.2 GBP payable at the station . Reference number is : HHBT7E2N .