answer: Mary comes to Tom's to return a book. Mary tells John the book is very interesting, then she leaves for shopping.
documents: #Person1#: Nice to see you, Mary! Come in, please!
  #Person2#: Thank you Tom, but I am afraid not now. I've come only to return the book borrowed from you.
  #Person1#: Wonderful. I've been waiting for you a long time and longing to know what you think of it.
  #Person2#: It is very interesting and I've learned a lot from it.
  #Person1#: Well, so it is with me.
  #Person2#: Oh, sorry. I can't go on talking about it with you any longer.
  #Person1#: It doesn't matter. Better stay here for another 10 minutes.
  #Person2#: No, I'll go and buy some food in the shop and I have to say goodbye to you.
  #Person1#: Goodbye.