using System;

using System.Security.Cryptography;

using System.Text;

public class Program

{   

    public static void Main()

    {

        var input = "15ad8bf87d26f62da953c4e225669e7e236d9fb631d10abdd83dda565486d08a3d26b4776ac99029";

        var output = "";

        using (var sha = SHA256.Create())

            {

                var bytes = Encoding.UTF8.GetBytes(input);

                Console.WriteLine(bytes);

                var hash = sha.ComputeHash(bytes);

                Console.WriteLine(hash);

                output = Convert.ToBase64String(hash);

            }       

        Console.WriteLine(output);

    }

}