I knew the best answer would blow my mind but wow this is something else! :O

Interesting. Briefly and clearly.

Wow. Impressed.

Он решил задачу математически, мы алгоритмически.

%9 is from maximum possible answer, i think, e.g. {0, 1, .., 9}

Сидел 40 минут и думал как решить, в итоге решил в 14 строк, а тут все просто оказывается

looks like some magic, is it allowed?..)

Please use spoiler flag next time.

great job!

Do not feel stupid.

The people who submitted this solution either googled it or knew the answer like knowing the solution to a brain teaser. They didn't realy come up with this as an answer on their own.

I have mad respect for the mathmatician who figured this out in the first place, not the people who parrot the answer.

Thank you!