question: Were M4 , M5 , and M6 written by a screenwriter that directed M1 and M2 and directed M3
query: SELECT count(*) WHERE {
  ?x0 a ns:film.writer .
  ?x0 ns:film.director.film M1 .
  ?x0 ns:film.director.film M2 .
  ?x0 ns:film.director.film M3 .
  M4 ns:film.film.written_by ?x0 .
  M5 ns:film.film.written_by ?x0 .
  M6 ns:film.film.written_by ?x0
  }