4 1 [ pos="255,30", style="filled", fillcolor=gray ];
5 2 [ pos="148,138", style="filled", fillcolor=gray ];
6 3 [ pos="41,138", style="filled", fillcolor=gray ];
10 3 -> 0 [ headlabel="3", labeldistance=4.5, labelangle=0.2854 ];
11 0 -> 3 [ headlabel="1", labeldistance=4.5, labelangle=-0.2854, color=red, fontcolor=red, style=dotted ];
12 3 -> 1 [ label="2", len=2.8 ];