Well that's weird. I'm not sure how to "Decrease either side every other row once ". To do something "once" makes it impossible to do it "every other row".
But here's my guess...
Row 1 - decrease on both sides.
Row 2 - work even
Row 3 - work even
Row 4 - work even
Row 5 - decrease on both sides.
Repeat row 1-5 9 times. :thinking: