Title of the Contest "Di.." reminded me famous Indian Song "Kolaveri Di". First I thought that this puzzle contest has some relationship with this song but later I found that it is named as "Di.." because all puzzle names in this contest start with Di.
Di... is part of the bi-annual contest held by Riad Khanmagomedov at Russian Puzzle Club 'Diogen'. Read more about Riad here
Puzzle #13 DIVISION has multiple solutions. Please do not solve the puzzle.