hello there . i am trying to locate a train for monday .
user
sure . where will you be going ?
assistant
i am going to cambridge .
user
all right , and where would you like to depart from ?
assistant
i'll will be leaving from london liverpool street .
user
i have got 10 trains that are on that route . do you have a preferred departure or arrival time ?
assistant
i need on that will leave london after 21:00 .