THEM: i need 2 books and 2 balls  YOU: i will giv you 2 balls and a hat  THEM: i need 2 books and the hat  YOU: i ned 2 books and 2 balls  THEM: no deal.  YOU: 2 books and a hat it is  THEM: 2 books and a hat for me?  YOU: 4 balls for me  THEM: deal.