class Polygon {
    private int[] sideLengths;

    public Polygon(int sides, int... lengths) {
        int index = 0;
        sideLengths = new int[sides];
        for (int length : lengths) {
            sideLengths[index] = length;
            index += 1;
        }
    }

    public int side(int number) {
        return sideLengths[number];
    }

    public int perimeter() {
        int total = 0;
        for (int index = 0; index < sideLengths.length; index += 1) {
            total += side(index);
        }
        return total;
    }
}

class Rectangle extends Polygon {
    public Rectangle(int l, int w) {
        super(4, l, w, l, w);
    }
    public int area() {
        return this.side(0)*this.side(1);
    }
}

class Square extends Rectangle {
    public Square(int l) {
        super(l, l);
    }
    // public int area() {
    //     return this.side(0)*this.side(1);
    // }
}

class Shapes {
    public static void main(String[] args) {
        Rectangle wreck = new Rectangle(3, 5);

        System.out.println(wreck.side(0)); // 3 1 point.
        System.out.println(wreck.side(1)); // 5 1 point.
        System.out.println(wreck.side(2)); // 3 1 point.
        System.out.println(wreck.side(3)); // 5 1 point.
        System.out.println(wreck.area()); // 15 1 point.
        System.out.println(wreck.perimeter()); // 16 1 point.

        Square nerd = new Square(7);

        System.out.println(nerd.side(0)); // 7 1 point.
        System.out.println(nerd.side(1)); // 7 1 point.
        System.out.println(nerd.side(2)); // 7 1 point.
        System.out.println(nerd.side(3)); // 7 1 point.
        System.out.println(nerd.area()); // 49 1 point.
        System.out.println(nerd.perimeter()); // 28 1 point.
    }
}