question: Who was a director and art director of M1 , M2 , and M3
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:film.director.film M1 .
  ?x0 ns:film.director.film M2 .
  ?x0 ns:film.director.film M3 .
  ?x0 ns:film.film_art_director.films_art_directed M1 .
  ?x0 ns:film.film_art_director.films_art_directed M2 .
  ?x0 ns:film.film_art_director.films_art_directed M3
  }