class Rectangle {
    constructor(w, h) {
        this.w = w;
        this.h = h;
    }
}

/*
 *  Write code that adds an 'area' method to the Rectangle class' prototype
 */
Rectangle.prototype.area = function() {
    this.area=this.w*this.h;
    return this.area;
}
/*
 * Create a Square class that inherits from Rectangle and implement its class constructor
 */
class Square extends Rectangle{
    constructor(side){
        super(side,side);
        this.side=side;        
    }
}

if (JSON.stringify(Object.getOwnPropertyNames(Square.prototype)) === JSON.stringify([ 'constructor' ])) {
    const rec = new Rectangle(3, 4);
    const sqr = new Square(3);
    
    console.log(rec.area());
    console.log(sqr.area());
} else {
    console.log(-1);
    console.log(-1);
}