Did M1 , M2 , M3 , M4 , M5 , M6 , and M7 star a art director
SELECT count(*) WHERE {
?x0 a ns:film.film_art_director .
M1 ns:film.film.starring/ns:film.performance.actor ?x0 .
M2 ns:film.film.starring/ns:film.performance.actor ?x0 .
M3 ns:film.film.starring/ns:film.performance.actor ?x0 .
M4 ns:film.film.starring/ns:film.performance.actor ?x0 .
M5 ns:film.film.starring/ns:film.performance.actor ?x0 .
M6 ns:film.film.starring/ns:film.performance.actor ?x0 .
M7 ns:film.film.starring/ns:film.performance.actor ?x0
}