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".

One of the problems was the robins.
acceptable

John gave Mary, and Joan presented to Fred, books which looked.
acceptable

The more obnoxious Fred, the less you should pay attention to him.

unacceptable