Depends on what the class was.
Class 1
I would attempt to get anything that fires a bullet, get as many knives as possible, and get to the roof. I would destroy the stairs with an axe, also.
Class 2
I would drive as far and as fast as I could, and if we ran into large traffic we would go by foot. I could collect ANY food and weapons as possible. I would also gather a sqquad, but not too big. Maybe 5 - 10 people.
Anything after a class 3 I would kill myself.