using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var foo = new ValueSortedKeyValuePairSet(){

            new KeyValuePair<int,string>(1,"aaa"),

            new KeyValuePair<int,string>(2,"aaaaaa"),

            new KeyValuePair<int,string>(3,"aa")

        };

        foreach(var t in foo) Console.WriteLine("Key: {0} Value: {1}", t.Key, t.Value);

    }

    public class ValueSortedKeyValuePairSet : SortedSet<KeyValuePair <int, string>> 

    {

        private class StringLengthComparerDecending : IComparer<KeyValuePair <int, string>>

        {

            public int Compare(KeyValuePair <int, string> x, KeyValuePair <int, string> y)

            {

                var lengthComparison = x.Value.Length.CompareTo(y.Value.Length);

                return lengthComparison == 0 ? string.Compare(x.Value, y.Value, StringComparison.Ordinal) : lengthComparison;

            }

        }

        public ValueSortedKeyValuePairSet() : base(new StringLengthComparerDecending()) {}

        public ValueSortedKeyValuePairSet(IEnumerable<KeyValuePair <int, string>> e) : base(e, new StringLengthComparerDecending()) {}      

    }

}