Bro

You even know how to use key in sorted function

it took me nearly as long as you, as long as you get it working in the end it's no biggie

That basically allows you to Increment by 2 in the for Loop, syntax is as follows:

for i in range(beginning, end, step)

Example: for i in range(0, 12, 2) will iterate through numbers 0 to 12 incrementing by 2 every iteration so (0, 2, 4, 6, 8, 10)

Try looking at this https://docs.codewars.com/training/troubleshooting/#works-but-no

input:
[1, 3, 2, 5, 7, 9, 4, 6, 8]
[4, 9, 8, 2, 6, 0, 3, 7, 5]
[7, 0, 6, 3, 8, 0, 2, 1, 9]
[6, 4, 3, 1, 5, 0, 7, 9, 2]
[5, 2, 1, 7, 9, 0, 8, 4, 6]
[9, 8, 0, 4, 2, 6, 5, 3, 1]
[2, 1, 4, 9, 3, 5, 6, 8, 7]
[3, 6, 0, 8, 1, 7, 9, 2, 4]
[8, 7, 0, 6, 4, 2, 1, 3, 5]
Expected result = False
Returns True

my code on the site returns True, but on my code editor returns False, is it bugged?

@akar-0 sorry, wont happen again

you need to put the 'return sum' inside your function