public class Graph {
    // instance variables go here:

    // constructor: n is the number of vertices, 
    // directed is a boolean which is true if the graph is directed,
    // false otherwise
    public Graph(int n, boolean directed) {

    }

    // startPoints are the starting points of edges, endPoints are the
    // ending points
    public void setEdges(int [] startPoints, int [] endPoints) {

    }

    public String toString() {
        return "";
    }
}

public class TestGraphs {
    public static void main(String [] args) {
	Graph g = new Graph(10,false); // undirected graph
	int [] starts = {0, 6, 3, 4, 2, 3, 5, 7, 8, 0, 9, 1};
	int [] ends = {1, 2, 0, 7, 3, 1, 2, 5, 6, 8, 4, 9};
	g.setEdges(starts, ends);
	System.out.println(g);
    }
}