digraph { dpi=200 node [shape=circle, style=filled] 0 -> 1 1 -> 0 1 -> 2 2 -> 1 2 -> 3 3 -> 2 3 -> 4 4 -> 3 4 -> 5 5 -> 4 5 -> 6 5 -> 14 6 -> 5 6 -> 7 7 -> 6 7 -> 8 7 -> 14 8 -> 7 8 -> 9 8 -> 13 9 -> 8 9 -> 10 9 -> 12 10 -> 9 10 -> 11 11 -> 10 11 -> 12 11 -> 15 12 -> 9 12 -> 11 12 -> 13 12 -> 16 13 -> 8 13 -> 12 13 -> 14 13 -> 17 14 -> 5 14 -> 7 14 -> 13 15 -> 11 15 -> 16 16 -> 12 16 -> 15 16 -> 17 17 -> 13 17 -> 16 }