normal 0 1 reverse 0 2 alternate 0 3 alternate-reverse 0 4 --> 2⅕x 12 0 50 50 vertical 12 1 50 50 vertical 12 2 50 50 vertical 12 3 50 50 vertical 12 4 50 50 vertical 11 4 50 50 vertical 11 3 50 50 vertical 11 2 50 50 vertical 11 1 <-- 2⅕x 11 0 --> 2x 10 0 50 50 vertical 10 1 50 50 vertical 10 2 50 50 vertical 10 3 50 50 vertical 10 4 50 50 vertical 9 4 50 50 vertical 9 3 50 50 vertical 9 2 50 50 vertical 9 1 <-- 2x 9 0 --> 1⅕x 8 0 50 50 vertical 8 1 50 50 vertical 8 2 50 50 vertical 8 3 50 50 vertical 8 4 <-- 1⅕x 7 0 50 50 vertical 7 1 50 50 vertical 7 2 50 50 vertical 7 3 50 50 vertical 7 4 --> 1x 6 0 50 50 vertical 6 1 50 50 vertical 6 2 50 50 vertical 6 3 50 50 vertical 6 4 <-- 1x 5 0 50 50 vertical 5 1 50 50 vertical 5 2 50 50 vertical 5 3 50 50 vertical 5 4 <-- ⅕x 3 0 --> ⅕x 4 0 50 50 vertical 3 1 50 50 vertical 4 1 50 50 vertical 3 2 50 50 vertical 4 2 50 50 vertical 3 3 50 50 vertical 3 4 50 50 vertical 4 3 50 50 vertical 4 4 <-- 0x 1 0 --> 0x 2 0 50 50 vertical 1 1 50 50 vertical 1 2 50 50 vertical 1 3 50 50 vertical 1 4 50 50 vertical 2 4 50 50 vertical 2 3 50 50 vertical 2 2 50 50 vertical 2 1