Let's try that same approach with either the image you were using in class or one of the following:
Paint the overall shape before you start counting individual boards. Chances are you won't need to put them all in.
Squint! See those buildings in the distance on the left? they are trying to be one shape. The lines of parked vehicles are also on the brink of being single shapes.
How many shapes comprise the shady side of the street? Hint: Point at the ceiling and look at your hand.
First, paint the pile, then the logs.