public static int flippingMatrix(List<List<Integer>> matrix) {
        int result = 0;
        int halfMatrixSize = matrix.size() / 2;
        int maxMatrixIndex = matrix.size() - 1;
            
        for (int row = 0; row < halfMatrixSize; row ++) {
            for (int col = 0; col < halfMatrixSize; col ++) {
                int element = matrix.get(row).get(col);
                int rightMirror = matrix.get(row).get(maxMatrixIndex - col);
                int downMirror = matrix.get(maxMatrixIndex - row).get(col);
                int rightDownMirror = matrix.get(maxMatrixIndex - row)
                .get(maxMatrixIndex - col);
                
                result += Arrays.asList(element, rightMirror, downMirror, rightDownMirror)
                .stream().max(Integer::compare).get();
            }
        }
        return result;
    }