I enjoyed this challenge but it's a bit confusing to see that the best answers are using built-in functions. I believe this kata is a 3 kyu challenge only if you don't use these built-in functions.

I only found one exemple of such a syntax in python: itemgetter(1,3,5)('ABCDEFG'), yet I don't get it...

Thanks for your answer, it drove me to look for the meaning of first-class values and I learned a lot. However, I don't feel closer to the solution... I believe that I can use a recursive function to obtain the right chained() function. However I'm still stuck to run it on the input. I'd appreciate another hint!

I dont't understand how a function can be written like that in Python: chained([functions])(input) and I have no idea about how I can retrieve 'input' to pass it in the chain... If someone could give me a slight indication about where I should look for a solutionm I'd appreciate!

Thanks! I guess I didn't get what was the 'signature of the function'...

Hey Redmega,
I like your Kata but I can't get the logic...
Here is were I got blocked:
10
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[1, 3, 5, 7, 9]
[1, 4, 7, 10]
[1, 5, 9]
[1, 5, 9] should equal [1, 4, 9]

It says should equal: [1, 4, 9] but in this case it seems that the step 'i' is uneven... 1+3 = 4 and then 4+5 = 9 so 'i' equals both 3 and 4? Did I miss something in the notes? Something like he starts from the last locker he changed the state?