TASK DEFINITION: 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".
PROBLEM: Springfield would have built a police station with the federal grant.

SOLUTION: acceptable

PROBLEM: I know a boy mad at John.

SOLUTION: acceptable

PROBLEM: Which packages is it possible that Sam didn't pick up which are to be mailed tomorrow until it had stopped raining?

SOLUTION:
unacceptable