Calculating Power Output Climbing Stairs

[africanmasks]

Homework Statement

Suppose your mass is 76.0 kg and you climb 40 stairs of height 18 cm in 19.0 s. What is your power output as you climb the stairs?

Homework Equations

Power = Work / change of time

The Attempt at a Solution

I need a hint on solving for the work. I tried solving for the kinetic energy, but my answer was wrong.

 

[mgb_phys]

Power is energy / time.
What is the change in energy between the top and bottom?
How long did it take to generate that energy.