Nice solution, I did almost the same but a few lines longer. This is how I first learned about the "Set" method.

I think, this type of answer must be "the best practices"

Good comment. I've tried to do the same solution, but then, like, wait a minute...what if the test will be not 27 or 153, what if
the number will be very huge, like 325352952095239525. It will be not optimal solution and take much more time.

Very good and elegant answer. Nice work

Very good answer. He deserves a like

Hmm,interesting. Ok, i'll remember it. Thank's for help

Hello, why my link is a spoiler? I post it at "answer section". I thought my comment can see only people, who resolve the problem or who used "unlock solution".

what the hell is going on?

Lol, nice)

Wow, that's cool, well done