(do* ((rest-lists lists (cdr rest-lists))
(list (car rest-lists) (car rest-lists))
(last-list (null (cdr rest-lists)) (null (cdr rest-lists))))
(do* ((rest-lists lists (cdr rest-lists))
(list (car rest-lists) (car rest-lists))
(last-list (null (cdr rest-lists)) (null (cdr rest-lists))))