What is the title of the film with the longest duration time and stars PENELOPE GUINESS?
longest duration of film refers to Max(length)
SELECT T3.title FROM actor AS T1 INNER JOIN film_actor AS T2 ON T1.actor_id = T2.actor_id INNER JOIN film AS T3 ON T2.film_id = T3.film_id WHERE T1.first_name = 'PENELOPE' AND T1.last_name = 'GUINESS' ORDER BY T3.length DESC LIMIT 1