If I know the initial velocity and the distance traveled before coming to a stop (velocity = 0) and assuming the (negative) acceleration is constant, how can I calculate the acceleration?

E.G.

I'm in a buggy going 100 feet/sec and there is a light 33 feet in front of me. How much (constant negative) acceleration do I need to come to a stop after 33 feet?

I can solve other problems, but when I know only the initial velocity and the distance traveled I can't seem to figure out how to calculate the acceleration.

-Thanks!