i need a train that leaves cambridge on thursday .
user
there are 202 trains leaving cambridge on thursday . would you like to narrow your search by destination and time ?
assistant
i am going to the stansted airport and i need to arrive by 21:30 .
user
when are you leaving ?
assistant
departure time does not matter , i just need to arrive at the stansted airport by 21:30 on thursday , and i need to depart from cambridge .
user
i have 16 train departures fitting your preferences . they leave every :40 of the hour starting at 5:40 to 20:40 , would you like me to book 1 of these ?
assistant
can i please have 1 at 19:40 . i will get there by 21:30 correct ?
user
yes , the 19:40 train will arrive at 20:08 . how many tickets would you like ?
assistant
i do not need tickets at the moment , but i do need the price and train id for that 19:40 departure , please .