i need a train on friday from the london liverpool street station .
user
there are 10 trains leaving that station on friday . what time would you like to travel ?
assistant
the train should leave after 17:15 and should go to cambridge .
user
there are 4 trains that leave after 17:15 . the tr9886 leaves at 17:39 from london liverpool street . would you like me to book you a seat ?
assistant
what is the arrival time ?