It's merely a misunderstanding between frkstyc and I. 
Hope you can appreciate it, since I have just learnt this methods in my Maths class to solve the "MOD" puzzle.

For the sake of the complextion to transform this Maths Method in to a
conventional one. I have no alternative but to  put up the source. 

Thank you!
Wish you a bright prospection in both ACM and life!