package proto;
import javax.swing.JFrame;

public class Main {

	public static void main(String[] args) {
		A ins[] = { new A(10), new B(5), new C(7), new D(8) };
		for (int i = 0; i < 4; i++) {
			System.out.println(ins[i].get());
		}
		JFrame frame=new JFrame("test");
	    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	    frame.setSize(400,400);
	    frame.setVisible(true);
	}

}