Value was either too large or too small for an unsigned byte

Getting the following error :

System.OverflowException has been thrown - Value was either too large or too small for an unsigned byte.

Does anyone have any idea how to fix it?

class MainClass
{
    public static void Main(string[] args)
    {
            int decValue = 2210;
            string bin = Convert.ToString(decValue, 2);
            string lowerbyte = bin.Substring(Math.Max(0, bin.Length - 16));

            if (lowerbyte.Length < 16)
            {
                lowerbyte = lowerbyte.PadLeft(16, '0');
            }


        Int16 circular = Convert.ToByte(CicrularLeftShift(lowerbyte, 3), 2);

            string xored = Convert.ToString((circular ^ 38556), 2).Substring(Math.Max(0, Convert.ToString((circular ^ 38556), 2).Length - 16));

            //converting final binary shift value to HEX
            string finalHex = Convert.ToString(Convert.ToInt32(xored, 2), 16).ToUpper();

        Console.WriteLine(finalHex);

    }

    private static string CicrularLeftShift(string key, int shift)
    {
        return key.Substring(shift, key.Length - shift) + key.Substring(0, shift);
    }
}