Sudoku

Try to fill every empty square with number from 1 to 9.



You must obey following rules:

1. Every row must contain numbers from 1 to 9.

2. Every column must contain numbers from 1 to 9.

3. Every 3x3 square must contain numbers from 1 to 9.



There's also a mysterious code. What could it be?

Psst. You can ask the developer.



Enjoy the game!