I like ur solution, need to keep in mind it

Ashamed
I didnt read output after solution, so now i understand how can behavior katas and it can be cause why have to no use mutable methods on input
thank you for patience, answer and kata

I think no one answer me for my stpd q, but after first part cata i understand what i need to do for solution, but what are in test array, that it made side effect on using methods, in google i just read that some of methods are immutable, some mutable, but i dont understand why it should uncorrect work with just delete last item on array pop()

join the question ++
but maybe in coursera has some free courses about ag and dm programming, just for me it will hard courses cause on Eng lang

Ok, ty for answer
That is meaning that i m not right way thinking

@Chrono79 #Chrono79 Chrono79 Sorry for disturb, but can i ask some q for find solution?

What kind of problem? I tried google, and have seen that DP have a lot problems
Give an advice for solution please

*** its was hard but i have solved it...
But best solution from pro is looking so easy =\ maybe im not so clever
Sorry, just want to share emotion