function solve()
{

    class Balloon {
        constructor(color, gasWeight) {
            this.color = color;
            this.gasWeight = Number(gasWeight);
        }

    }

    class PartyBalloon extends Balloon {
        constructor(color,gasWeight,ribbonColor, ribbonLength) {
            super();
            this.ribbonColor = ribbonColor;
            this.ribbonLength = Number(ribbonLength);
            this.ribbon = {
                color: this.ribbonColor,
                length: this.ribbonLength
            };
        }

        get ribbon() {
            return this._ribbon;
        }

        set ribbon(ribbon) {
            this._ribbon=ribbon;
        }

    }

    class BirthdayBalloon extends PartyBalloon {
        constructor(color,gasWeight,ribbonColor, ribbonLength,text) {
            super();
            this.text = text;
        }

        get text() {
            return this._text;
        }

    }

    return {
        Balloon: Balloon,
        PartyBalloon: PartyBalloon,
        BirthdayBalloon: BirthdayBalloon
    }

}