import javax.swing.*;
import java.awt.*;

class Program extends JFrame {
	Program() {
		getContentPane().add(new SajatKomponens());
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setSize(800, 600);
		setVisible(true);
	}
	
	public static void main(String args[]) {
		new Program();
	}
	public class SajatKomponens extends JComponent {
		public void paint(Graphics g) {
			g.setColor(Color.blue);
			g.drawRect(10, 10, 50, 50);
		}
	}
}