question: Did a film star M1 , M2 , M3 , and M4 and star M6 's Mexican art director
query: SELECT count(*) WHERE {
  ?x0 a ns:film.film .
  ?x0 ns:film.film.starring/ns:film.performance.actor ?x1 .
  ?x0 ns:film.film.starring/ns:film.performance.actor M1 .
  ?x0 ns:film.film.starring/ns:film.performance.actor M2 .
  ?x0 ns:film.film.starring/ns:film.performance.actor M3 .
  ?x0 ns:film.film.starring/ns:film.performance.actor M4 .
  ?x1 ns:film.film_art_director.films_art_directed M6 .
  ?x1 ns:people.person.nationality ns:m.0b90_r
  }