c# dictionary<> with keys custom order

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// ----------------------------------------
// Program.cs file:
// ----------------------------------------

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        IDictionary<int, char> dictionary = new SortedDictionary<int, char>(new KeyComparer());

        dictionary.Add(1, 'c');
        dictionary.Add(2, 'b');
        dictionary.Add(3, 'a');

        foreach (KeyValuePair<int, char> pair in dictionary)
            Console.WriteLine(pair.Key + " " + pair.Value);
    }
}

// Output:
//
//     3 a
//     2 b
//     1 c


// ----------------------------------------
// KeyComparer.cs file:
// ----------------------------------------

using System.Collections.Generic;

public class KeyComparer : IComparer<int>
{
    public int Compare(int x, int y)
    {
        return y - x;
    }
}