;Goal: 
Convert UPC bar codes to decimal.


Specifically:

The [[wp:Universal_Product_Code|UPC]] standard is actually a collection of standards -- physical standards, data format standards, product reference standards... 

Here,   in this task,   we will focus on some of the data format standards,   with an imaginary physical+electrical implementation which converts physical UPC bar codes to ASCII   (with spaces and   '''#'''   characters representing the presence or absence of ink).


;Sample input:
Below, we have a representation of ten different UPC-A bar codes read by our imaginary bar code reader:
<pre>
         # #   # ##  #  ## #   ## ### ## ### ## #### # # # ## ##  #   #  ##  ## ###  # ##  ## ### #  # #       
        # # #   ##   ## # #### #   # ## #   ## #   ## # # # ###  # ###  ##  ## ###  # #  ### ###  # # #         
         # #    # # #  ###  #   #    # #  #   #    # # # # ## #   ## #   ## #   ##   # # #### ### ## # #         
       # # ##  ## ##  ##   #  #   #  # ###  # ##  ## # # #   ## ##  #  ### ## ## #   # #### ## #   # #        
         # # ### ## #   ## ## ###  ##  # ##   #   # ## # # ### #  ## ##  #    # ### #  ## ##  #      # #          
          # #  #   # ##  ##  #   #   #  # ##  ##  #   # # # # #### #  ##  # #### #### # #  ##  # #### # #         
         # #  #  ##  ##  # #   ## ##   # ### ## ##   # # # #  #   #   #  #  ### # #    ###  # #  #   # #        
        # # #    # ##  ##   #  # ##  ##  ### #   #  # # # ### ## ## ### ## ### ### ## #  ##  ### ## # #         
         # # ### ##   ## # # #### #   ## # #### # #### # # #   #  # ###  #    # ###  # #    # ###  # # #       
        # # # #### ##   # #### # #   ## ## ### #### # # # #  ### # ###  ###  # # ###  #    # #  ### # #         
</pre>
Some of these were entered upside down, &nbsp; and one entry has a timing error.


;Task:
Implement code to find the corresponding decimal representation of each, rejecting the error. 

Extra credit for handling the rows entered upside down &nbsp; (the other option is to reject them).


;Notes:
Each digit is represented by 7 bits:
<pre>
    0:  0 0 0 1 1 0 1
    1:  0 0 1 1 0 0 1
    2:  0 0 1 0 0 1 1
    3:  0 1 1 1 1 0 1
    4:  0 1 0 0 0 1 1
    5:  0 1 1 0 0 0 1
    6:  0 1 0 1 1 1 1
    7:  0 1 1 1 0 1 1
    8:  0 1 1 0 1 1 1
    9:  0 0 0 1 0 1 1
</pre>
On the left hand side of the bar code a space represents a '''0''' and a '''#''' represents a '''1'''. 
<br>On the right hand side of the bar code, a '''#''' represents a '''0''' and a space represents a '''1''' 
<br>Alternatively (for the above): &nbsp; spaces always represent zeros and '''#''' characters always represent ones, but the representation is logically negated -- '''1'''s and '''0'''s are flipped -- on the right hand side of the bar code.



;The UPC-A bar code structure:
::* &nbsp; It begins with at least 9 spaces &nbsp; (which our imaginary bar code reader unfortunately doesn't always reproduce properly), 
::* &nbsp; then has a &nbsp; &nbsp; ''' # # ''' &nbsp; &nbsp; sequence marking the start of the sequence, 
::* &nbsp; then has the six "left hand" digits, 
::* &nbsp; then has a &nbsp; ''' # # ''' &nbsp; sequence in the middle, 
::* &nbsp; then has the six "right hand digits",  
::* &nbsp; then has another &nbsp; ''' # # ''' &nbsp; (end sequence), &nbsp; and finally, 
::* &nbsp; then ends with nine trailing spaces &nbsp; (which might be eaten by wiki edits, and in any event, were not quite captured correctly by our imaginary bar code reader).


Finally, the last digit is a checksum digit which may be used to help detect errors. 


;Verification:
Multiply each digit in the represented 12 digit sequence by the corresponding number in &nbsp; (3,1,3,1,3,1,3,1,3,1,3,1) &nbsp; and add the products.

The sum (mod 10) must be '''0''' &nbsp; (must have a zero as its last digit) &nbsp; if the UPC number has been read correctly.
<br><br>