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: Suddenly an ugly old man entered the hall.

SOLUTION: acceptable

PROBLEM: A big green insect flew into the soup.

SOLUTION: acceptable

PROBLEM: The policeman kissed the puppy.

SOLUTION:
acceptable