using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        SortedList<int, string> planets = new SortedList<int, string>();

​

        // Sorted automatically by key

        planets.Add(2, "Venus");

        planets.Add(1, "Mercury");

        planets.Add(3, "Earth");

        //To print key and value

        foreach (var item in planets)

        {

            Console.WriteLine($"{item.Key}, {item.Value}");

        }

    }

}