Write a Emacs-lisp function that takes two parameters. You can assume that the first one is a list and the second one a non-negative number. The function must return the i-th element of the list. We'll assume that the car of the list is the element number 0, the next one is number 1, and so on. If the index is higher than the length of the list, the function should return nil. Implementation suggestion: you can use either the loop dolist with a counter, or the loop dotimes in combination with the function pop. Recursion also works.