answer: #Person2# tells #Person1# the train to Wall Street and asks #Person1# to let people off before #Person1# getting on.
documents: #Person1#: Excuse me, how do I get to Wall Street?
  #Person2#: Take the A train south to the Liberty Ave. stop. You should be able to find it from there.
  #Person1#: I'm sorry, but how do I know the subway train is going south?
  #Person2#: The southbound A trains say Brooklyn.
  #Person1#: O. K. , so it's this one?
  #Person2#: Yeah. Hey? What are you doing? Let the people off the train before you get on.
  #Person1#: Oh, sorry.
  #Person2#: Jeez. Tourists.