public ActionResult Subtract(TwoByTwoMatrix[] inputMatrices)
        {
            if (ModelState.IsValid)
            {
                TwoByTwoMatrix firstMatrix  = inputMatrices[0];
                TwoByTwoMatrix secondMatrix = inputMatrices[1];

                TwoByTwoMatrix resultMatrix = firstMatrix.Subtract(secondMatrix);

                return(View("Result", resultMatrix));
            }

            return(View(inputMatrices));
        }