i want a train leaving from london liverpool street .
user
i can help with that . what is the destination ?
assistant
my destination is cambridge , and i'll be traveling on saturday .
user
is there a time you would like to leave or arrive by ?
assistant
i would leave after 14:45 .
user
i have a train that leaves at 15:39 and arrives and 17:07 . would you like me to book that for you ?
assistant
yes please make a booking for 4 people .