THEM: i need the hat and 2 books  YOU: i can gladly give you the books but not the hat  THEM: i have to have the hat, and 1 book  YOU: no hat, three books  THEM: no hat, no deal. i have to have the hat, you can have the rest  YOU: 2 books, one ball  THEM: nope, no hat no deal.  YOU: one hat nothing else?  THEM: sure  YOU: deal.