using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    static Dictionary<char, int> myDict = new Dictionary<char, int>

        {

            ['a'] = 5, 

            ['b'] = 4, 

            ['c'] = 0

        };

    public static void Main(string[] args)

    {

        var md = myDict.OrderBy(md => md.Value).ToDictionary(md => md.Key, md => md.Value);

        foreach (var m in md)

            Console.Write($"{m.Key}={m.Value} ");

    }

}