THEM: can i get two hats and two balls?  YOU: no, i need all 3 balls and the books  THEM: you can have the three balls if i can have the rest  YOU: i need 3 balls and 1 book  THEM: no i need both books and at least one other thing  YOU: both books and the hat  THEM: i need both books and the hat which would leave you with the three balls.