Thanks for the translation. Also, C107 might not have a doujinshi but author is blessing us with their wedding album! Already made the purchase and looking forward to receiving it!
To those saying that the math is wrong, it's actually correct. Just that the translation makes it look wrong
First line is 5 (as in the tens column), leaving 12 as the second line. Putting 2 at the ones column leaves a remainder of 2.