It's little more than converting a math equation to your language's syntax

thanks, glad you enjoyed it :)

You can use print at the start of function to find out. See: https://docs.codewars.com/training/troubleshooting/#print-input

Not a kata issue, it's stated in the description what to do:

The highest/lowest element is respectively only one element at each edge, even if there are more than one with the same value!

In that case, the minimum is 0 and the maximum is 10, the remaining numbers as 1, 6 and 10 and their sum is 17.

All languages or only Python?