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 lifted onto the table.

Ex Output:
unacceptable


Ex Input:
That few boys came upset any of the teachers.

Ex Output:
unacceptable


Ex Input:
The proof that this set is recursive is difficult.

Ex Output:

acceptable