soo true, i just skip all of his katas

This could well be a kata issue but you really need to provide more details.

I have to agree with your comment. His explanation is just with one line but it exress better all description in the task.

Not all smart guy can be a teacher with same reason ^^.

hi, try my mine please, I think I achieved the best speed result

Good observation!

If you don't like something, you just need to click on next kata at top right of the page.

Instead of complaining you can propose something human-readable and I will see if I can take it:-) Cheers.

It makes even less sense to tell someone that, from your point of view, there is no point in something.

PS Absolutnie nie rozumiesz, co napisałeś w swoim języku?
Może mój angielski nie jest idealny, ale nie widzę sensu wskazywania mi tego!
xD A rosyjski ślad to co rosja robi na Donbasie!

hey martynov-94, what's the sense of your message?

This statement is hardly obvious

...the fact is that not every decision made slowly will work quickly!

I respectfully disagree that it's another 'find the formula problem'. The author explicitly noted that we try to solve it without using a loop. Obviously, we can solve it with a loop but we need to try to come up with another algorithm. This is about optimization and, believe me, it matters. A couple of days back I had an interview for a developers role where they asked me questions about algorithms and optimization.

I'm really noob at math, but this problem is like Number Pattern

Please use spoiler flag next time.