FirstCoffe.ts

class Espresso extends Beverage {
  constructor() {
    super();
    this.description = "에스프레소~";
  }
  cost() {
    return 3000;
  }
}

class Americano extends Beverage {
  constructor() {
    super();
    this.description = "아메키라노~";
  }
  cost() {
    return 4000;
  }
}