HOW TO PRINT ON 2 SIDES WITHOUT MINDFUCK
        your print out
        +-----------+
        |           |        filp page, as you would flip the page in book
        |           |         don't rotate; just flip it like a book, and put it to paper input without rotating
        |           |                 THAT'S IT!
        |           |
        |           |
        |           |
        |         <-|--
        +-----------+ 


        The order matter; print all EVEN pages first, re-insert; print all ODD next
                        you get pages in order and flipped
        
        Even -> Odd -> File (ready)
            EOF - End Of File