ALGORITHMS how to open a door

First of all, you need to know that there are different types of doors and knobs, there are the ones with a round shaped knob or the ones with an horizonltal and flat shape.

START:

Stan one step away from the door.
Lay your hand on the knob.
Press down if its a flat knob or twist it to the right if it has a circular shape.
Then just push the knob towards you and the door will open.

STOP.