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:
Not many books survived the fire, did they?

Ex Output:
acceptable


Ex Input:
Copper rods bend easily.

Ex Output:
acceptable


Ex Input:
I saw Mary and downtown yesterday your friend from Boston.

Ex Output:

unacceptable