2

class MyCollection : Dictionary<int, Pair>
    {
        public void Print()
        {
            foreach (var i in Keys)
                Console.WriteLine("Key = {0}, value = {1}", i, this[i]);
        }

        public void Add(int key, Pair valuee)
        {
            base.Add(key, valuee);
        }
    }


class Program
    {
        static void Main(string[] args)
        {
            Pair p = new Pair(1, 2);
            MyCollection mc = new MyCollection();
            mc.Add(10, p);
            mc.Print();
        }
    }