Can anyone please tell me where this problem is from? Has anyone solved this before?

Thanks!
Can anyone please tell me where this problem is from? Has anyone solved this before?

Thanks!
So you don’t want to know how to solve the problem, you want to know where it is from?
I was able to solve it. I want to know if anyone has seen similar problems or this one somewhere else, like in russian olympiads or kazakh olympiads etc.