Define a function, (my-reverse li), that accepts a list and returns the reverse of the list.

The function should only process an input list. You can assume that the input list will contain no nested list.

You are NOT allowed to define another function. Use ONLY the basic elements of Scheme - define, car, cdr, list?, null? and cons.

example input: (my-reverse '(1 2 3 4))

Output: '(4 3 2 1)