using System;

public class Program

{

    private static Random random = new Random();

    private static void Shuffle<T>(T[] array) 

    {

        if (array is null)

            throw new ArgumentNullException(nameof(array));

        for (int i = 0; i < array.Length - 1; ++i) 

        {

            int r = random.Next(i, array.Length);

            (array[r], array[i]) = (array[i], array[r]);

        }

    }       

    public static void Main()

    {

        char[] demo = new char[] {'a', 'b', 'c', 'd', 'e'};

        Shuffle(demo);

        Console.WriteLine($"[{string.Join(", ", demo)}]");

    }

}