digraph test {
    height=5;
	ratio="fill";
	node [color="#918194", fillcolor="#f1e1f4", style="filled"];
	edge [color="red"];
	node1 [label="L=1", shape="diamond"];
	node2 [label="a", shape="box"];
	node3 [label="b", shape="box"];
	node4 [filllcolor="yellow", label=" ", shape="circle", style="filled"];
	entry [fillcolor="white", label="entry", shape="plaintext", style="filled"];
	exit [fillcolor="white", label="exit", shape="plaintext", style="filled"];
	node1 -> node2 [label="Y"];
	node1 -> node3 [label="N"];
	node2 -> node4;
	node3 -> node4;
	node4 -> exit;
	entry -> node1;
}