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".

Carla shoveled the walk of snow.
unacceptable

I am anxious that you should arrive on time.
acceptable

This hat it is certain that he was wearing.

acceptable