digraph G {
size="7.5,10";
node [fontsize=10,height=.2,width=.3];
edge [len=1];
"0" [style=bold];
5->4;
4->15;
15->14;
14->7;
7->13;
13->8;
8->1;
1->12;
12->10;
10->9;
9->2;
2->12;
12->11;
11->8;
8->3;
3->7;
7->0;
0->15;
15->6;
6->5;
}