digraph finite_automata {
 /* graph properties */
 graph [rankdir=LR label="ones_even.fa"];
 node [style=filled fillcolor="#E0E0E0"];
 /* states */
 e [shape=doublecircle];
 odd [shape=circle];
 invis_start [style=invis];
 /* transitions */
 invis_start -> e [label=" "];
 e -> e [label="0"];
 e -> odd [label="1"];
 odd -> e [label="1"];
 odd -> odd [label="0"];
}