You're given a sentence and your task is to classify whether the sentence is acceptable or not. Any sentence which is grammatically correct, has a naturalistic text, is written by a native speaker and which minimizes superfluous content is acceptable, otherwise unacceptable. If the sentence is acceptable then write "acceptable", otherwise "unacceptable".

Ex Input:
Robert knows it is essential that he is well behaved.

Ex Output:
acceptable


Ex Input:
Willy is taller than Bill by as much as I know a boy who thinks that Bill is taller than Dan.

Ex Output:
unacceptable


Ex Input:
I lent the book all the way to Tony.

Ex Output:

unacceptable