3

class Money : Pair
    {
        ...
        public override bool Equals(object obj)
        {
            Pair pair = obj as Pair;
            return first == pair.First && second == pair.Second;
        }
    }



class Program
    {
        static void Main(string[] args)
        {
            Pair p2 = new Pair(4, 5);
            MyCollection mc1 = new MyCollection();
            mc1.Add(5, p2);
            Pair p3 = new Pair(8, 5);
            bool check = mc1.ContainsValue(p3);
            Money m1 = new Money(11, 22);
            mc1.Add(4, m1);
            check = mc1.ContainsValue(m1);
            bool findKey = mc1.ContainsKey(11);
            mc1.Print();
            Console.WriteLine(check + " " + findKey);
        }
    }