class Pair<T, W>
        {
            private T _Key;

            public T Key
            {
                get { return _Key; }
                set { _Key = value; }
            }

            private W _Value;

            public W Value
            {
                get { return _Value; }
                set { _Value = value; }
            }

            public Pair(T key, W value)
            {
                this.Key = key;
                this.Value = value;
            }
	
        }