i would like details about trains leaving from cambridge and going to ely .
user
there are 70 scheduled trains on that route . do you have a day or time you wish to travel ?
assistant
i'll be traveling on monday and i would like to leave after 15:00 .
user
what time do you need to arrive by ?
assistant
it does not matter , just so it leaves after 15:00 . i'll just need the train id and arrival time please .
user
the tr7177 leaves at 15:50 , do you want tickets ?
assistant
no thank you . i would like to know the arrival time , though .