One optimization problem with escalator

I do not usually stand on a moving escalator and go through it.
I want to pass the maximum number of steps. Up or Down!
What is the speed (steps per second) should I go?
One symbolic and numeric solution I need (from my students too) 
PS
The largest escalator in the world is located in Moscow, at the metro station "Victory Park". Its length is 126 meters and height of 63.4 m.
Escalator speed - 45 meters per minute
The width of the steps of the escalator - 0.4 m

