https://i.sstatic.net/0uiuqoCY.png
I’m writing an array and I want to sort it in algobuild

I tried like in the photo but I didn’t expect the error
I can’t understand why is out of range if I made the assignment k is equal to j.
I’m pretty bad in doing this and I want help. if I don’t write some more lines it won’t make me post the question