Did M2 and M3 star a American art director of M1
SELECT count(*) WHERE {
?x0 ns:film.film_art_director.films_art_directed M1 .
?x0 ns:people.person.nationality ns:m.09c7w0 .
M2 ns:film.film.starring/ns:film.performance.actor ?x0 .
M3 ns:film.film.starring/ns:film.performance.actor ?x0
}