using System;
using System.Collections.Generic;

class Program
{
    static void Main(string[] args)
    {
        var list = new List<KeyValuePair<int, string>>();

        list.Add(new KeyValuePair<int, string>(31, "Jan"));
        list.Add(new KeyValuePair<int, string>(28, "Feb"));
        list.Add(new KeyValuePair<int, string>(31, "Mar"));
        list.Add(new KeyValuePair<int, string>(30, "Apr"));
        list.Add(new KeyValuePair<int, string>(31, "Jan"));

        //list.Sort(delegate(KeyValuePair<int, string> kvp1, KeyValuePair<int, string> kvp2)
        //{
        //    return kvp2.Key - kvp1.Key;
        //});
        list.Sort((KeyValuePair<int, string> kvp1, KeyValuePair<int, string> kvp2) => (kvp2.Key - kvp1.Key));

        foreach (var kvp in list)
        {
            Console.WriteLine("{0} {1}", kvp.Key, kvp.Value);

        }
    }
}