public async Task <ActionResult> UploadMatrix(HttpPostedFileBase file)
        {
            if (file != null)
            {
                var matrix = await _matrixService.ToMatrixAsync(file.InputStream);

                try
                {
                    await _matrixService.WriteMatrixAsync(matrix);
                }
                catch (ArgumentOutOfRangeException)
                {
                    return(RedirectToAction("Index", "Home", new { Error = "Матрица не квадратная" }));
                }
            }

            return(RedirectToAction("Index", "Home"));
        }