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".

Q: Students objected to the teacher.

A: acceptable
****
Q: Bob proved that this set is recursive.

A: acceptable
****
Q: Robin arrived all the way at the station.

A:
unacceptable
****