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 man surrounded the fort.
unacceptable

They let him go yesterday, he.
unacceptable

He bought a bench on which to sit.

acceptable