Press the space bar to put the pen up press 1 to put the pen down press 0 to erase everything press 2 to change color by -5 press 3 to change color by 5 press 4 to change pen size by -1 press 5 to change pen size by 1 press 6 to change color to black press 7 to change color to white press 8 to change back its normal color I worked hard on this so I hope you enjoy it :-D ------------------------------------------------------------------------
thanks to @1h2i4 for suggesting to put the tip of the pencil in the middle point
