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".

Every student answered any question.
unacceptable

Mary's happy with her work, and John's with his children.
acceptable

Any pilot could be flying this plane.

acceptable