Bx8 7 X1 Cx4 3 X1 2 X1 1 X2 5 X1 4 X2 6 X2 A x4 Step1 Dx 6 Step2 6 6 1 B 1 B 5 B B C C Step3 Step4 Step5 C C 4 B 3 B B A A B A A A A A 2 A D D D D D D