The blue rectangles should be in numeric order and form a "D". (Boxes labelled "A" should be in the first column; boxes labelled "B" should be in the second; arrows indicate the correct alignment.)

⇦ A 1
⇦ A 3
⇦ A 5
⇦ A 7
⇦ A 9
⇦ B 2
B 4 ⇨
B 6 ⇨
B 8 ⇨
⇦ B 10