Draw the structure for the following dotted lists, and then write the list as it would be output in lisp (as close to a proper list as possible).

1. (a . (b . (c . nil)))

2. ((a . (b . nil)) . ((c . nil) . nil))

3. ((a . b) . ((c . d) . nil))

4. (a . ((b . c) . (d . nil)))