public static void Main()
  {
	Environment.ExitCode=1;

	Console.WriteLine("Test should pass with ExitCode 0");
	Console.WriteLine("Building Graph with 100 vertices...");
	Graph MyGraph = new Graph(100);  // graph with 10 nodes

	MyGraph.BuildGraph();    
	MyGraph.CheckIfReachable();

	Console.WriteLine("Deleting all vertices...");

	MyGraph.DeleteVertex();

	GC.Collect();
	GC.WaitForPendingFinalizers();

	Console.WriteLine("Done...");
	
  }
  public static void Main()
  {
	Graph.flag=false;
        Environment.ExitCode = 0;

	Console.WriteLine("Test should pass with ExitCode 0");
	Console.WriteLine("Building Graph with 100 vertices...");
	Graph MyGraph = new Graph(100);  

	MyGraph.BuildGraph();    
	MyGraph.CheckIfReachable();

	Console.WriteLine("Deleting all vertices...");

	MyGraph.DeleteVertex();

	GC.Collect();
	GC.WaitForPendingFinalizers();

	Vertex temp = MyGraph.ReturnVfirst();	
	GC.KeepAlive(temp);	// will keep alive the graph till here

	Console.WriteLine("Done...");
	Graph.flag=true;	// to check if finalizers ran at shutdown or earlier
	
  }