using System;

using System.Linq;

using System.Xml;                   

using System.Xml.Linq;

using System.Collections; 

using System.Collections.Generic;

using System.Data;

using System.Data.DataSetExtensions;

using System.Data.Linq;

using System.Text;

using System.Text.RegularExpressions;

using System.Xml.Serialization; 

using System.IO;

using System.Globalization;

using System.Diagnostics;

public class Program

{

    public static void Main()

    {

           var dictionary = new Dictionary<string, int>(5);

        dictionary.Add("cat", 3);

        dictionary.Add("dog", 1);

        dictionary.Add("mouse", 0);

        dictionary.Add("elephant", 2);

        dictionary.Add("bird", 4);

        var result = dictionary

            .Take(1)

            .Concat(dictionary

                    .Skip(1)

                    .OrderBy(o=>o.Value))

            .Select(x=>x.Key);

​

        result.Dump();

    }

}