divide the UPC into 4 groups of three digits
use the scheme below to translate each digit into its output



    1  2  3

0   C3 n  Z  
1   CN j  Y  
2   Cx f  X  
3   Ch b  W  
4   D3 D  3  
5   DN z  2  
6   Dx v  1  
7   Dh r  0  
8   E3 T  7  
9   EN P  6