Definition: Given a negotiation between two participants, answer 'Yes' if both participants agree to the deal, otherwise answer 'No'.
Input: THEM: you take balls, and i keep the rest  YOU: can i also have a book?  THEM: books are zero to me  YOU: so you just want the hat and that's it?  THEM: no i meant without books i will have sero  YOU: oh, can i have either the hat or a book too?  THEM: just one book and all balls for you  YOU: deal.
Output:
Yes