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:
I know which book Mag read, and which book Bob discussed after I had.

Ex Output:
unacceptable


Ex Input:
I bought the parrot in the store.

Ex Output:
acceptable


Ex Input:
The problem knows easily.

Ex Output:

unacceptable