question: Which film editor executive produced a film edited by M3 , M4 , M5 , and M6 and directed M1
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.editor .
  ?x0 ns:film.director.film M1 .
  ?x0 ns:film.producer.films_executive_produced ?x1 .
  ?x1 a ns:film.film .
  ?x1 ns:film.film.edited_by M3 .
  ?x1 ns:film.film.edited_by M4 .
  ?x1 ns:film.film.edited_by M5 .
  ?x1 ns:film.film.edited_by M6
  }