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".

John kept him behind the garage.
acceptable

Who do you wonder what bought?
unacceptable

Ellen conferred with Helen about the problem.

acceptable