for example, commented each `move(10 * (10 - 5))` nodes. now, generate below. ```ruby # move ( ) steps # * # - move(10 * (10 - 5)) ``` in the future, below is for example. ```ruby # move () steps # ≫ * # ≫≫ - move(10 * (10 - 5)) ``` It's one of idea.