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 offers few advice.
unacceptable

One of the problems was the robins.
acceptable

This key will open the door to the linguistics building.

acceptable