Translated instructions for russian version:

- think of any two digit number
- subtract from it digits which its made of (for example if you thought of 54 you need to subtract 4 and 5, result will be 45)
- find that number and its symbol in the table
- think about that symbol
- Click on large big square above the table.

How does it work ? If you want, time yourself the answer is really rather simple.

Note: Comments may have spoilers! Come up with solution on your own before reading them.