public class TestDigraph {
    public static void main(String[] args) {

	Digraph g = new Digraph();
	g.addVertex("A");
	g.addVertex("B");
	g.addVertex("C");
	g.addEdge("A","B",27);
	g.addEdge("A","A");
	g.addEdge("A","C");
	g.addEdge("B","C");
	System.out.println(g);

    }



}