class Money : Pair
    {
        protected int rubles, kopeks;
        public int Rubles
        {
            get { return rubles; }
            set { rubles = value; }
        }

        public int Kopeks
        {
            get { return kopeks; }
            set { kopeks = value; }
        }

        public Money()
            : base()
        { rubles = 0; kopeks = 0; }

        public Money(int r, int k)
            : base(r, k)
        { rubles = r; kopeks = k; }

        public override string ToString()
        {
            return rubles + "p. " + kopeks + "kop. ";
        }
    }