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".

Willy is taller than that Bill is is generally believed.
unacceptable

The door hinges squeaked.
acceptable

The jeweller scribbled his name on the contract.

acceptable