answer: #Person1# and #Person2# will join in John's mountaineering trip.
documents: #Person1#: Have you decided where to go for the vacation?
  #Person2#: I will join John in his mountaineering trip.
  #Person1#: Woo cool. Which mountain are you going to conquer?
  #Person2#: We haven't made up our minds. Will you come with us?
  #Person1#: Of course, I will.