public async Task <ActionResult <string> > CalculateMatrix(Input input)
        {
            string matrixLeftStr = await dataServer.GetMatrixAsync(input.matrixLeft);

            string matrixRightStr = await dataServer.GetMatrixAsync(input.matrixRight);

            int[,] leftMatrix  = JsonConvert.DeserializeObject <int[, ]>(matrixLeftStr);
            int[,] rightMatrix = JsonConvert.DeserializeObject <int[, ]>(matrixRightStr);

            if (leftMatrix == null || rightMatrix == null)
            {
                return(BadRequest());
            }

            try
            {
                int[,] multipliedMatrix = MatrixTool.MultiplyMatrix(leftMatrix, rightMatrix);
                int[,] resultMatrix     = new int[input.rowEnd - input.rowBeg, input.colEnd - input.colBeg];

                uint row = 0;
                uint col = 0;
                for (uint i = input.rowBeg; i < input.rowEnd; i++)
                {
                    for (uint j = input.colBeg; j < input.colEnd; j++)
                    {
                        resultMatrix[row, col] = multipliedMatrix[i, j];
                        col++;
                    }
                    col = 0;
                    row++;
                }

                return(Ok(JsonConvert.SerializeObject(resultMatrix)));
            }
            catch
            {
                return(BadRequest());
            }
        }