conversations.from: human
conversations.value: Henry needs to declutter his book collection of 99 books.  From his bookshelf, he was able to fill 3 boxes of 15 books each to take to a donation center.  He had 21 books in a room he could donate, 4 on his coffee table and 18 cookbooks stashed in the kitchen.  When he dropped them off, he noticed a box of books that had a  "free to a good home" note.  He grabbed 12 books to take back to his place.  How many books does Henry now have?
  How to solve this?
conversations.from: assistant
conversations.value: He filled 3 boxes with 15 books each so 3*15 = 45 books
  From the rest of his house he is donating 45+21+4+18 = 88 books for donation
  His collection is 99 books and he is donating 88 books, so that leaves him with 99-88 = 11 books
  He picks up 12 books to add to his collection of 11 books so he now has 12+11 = 23 books