import java.util.ArrayList;

public class BouncingBalls {
    public static void main(String[] args) {
        int N = 40;
        ArrayList<Ball> allBalls = new ArrayList<Ball>();
        for (int i = 0; i < N; i++) {
            allBalls.add(new Ball());
        }

        PennDraw.setCanvasSize(600, 600);
        PennDraw.enableAnimation(30);
        while (true) {
            PennDraw.clear();
            for (int i = 0; i < N; i++) {
                Ball current = allBalls.get(i);
                current.draw();
                current.update();
            }
            PennDraw.advance();
        }
    }
}