A scientist uses a submarine to study ocean life.

She begins at sea level, which is an elevation of 0 feet.
She descends for 91 seconds at a speed of 2.2 feet per second.
She then ascends for 32 seconds at a speed of 0.7 feet per second.

At this point, what is her elevation, in feet?

0 - (91 * 2.2) + (32 * .07) = ?