answer: #Person1# assists #Person2# to buy a piece of nylon clothes and a pair of trousers for #Person2#'s son.
documents: #Person1#: What can I do for you?
  #Person2#: I want to buy a sweater for my son. This yellow one doesn't have a price on it. How much does it cost? Do you know?
  #Person1#: Yes, it's $ 42.33.
  #Person2#: That's too expensive.
  #Person1#: Here's a nice nylon one for $ 15.88. We sell a lot of these.
  #Person2#: Yes, it is nice. I think I'll take it.
  #Person1#: Do you want anything else? This kind of trousers is in discount. It only costs $ 13 each pair.
  #Person2#: That's nice. OK, I'll take one.