question: Were M3 , M4 , M5 , and M6 written by a actor that wrote M1 and executive produced M2
query: SELECT count(*) WHERE {
  ?x0 a ns:film.actor .
  ?x0 ns:film.producer.films_executive_produced M2 .
  ?x0 ns:film.writer.film M1 .
  M3 ns:film.film.written_by ?x0 .
  M4 ns:film.film.written_by ?x0 .
  M5 ns:film.film.written_by ?x0 .
  M6 ns:film.film.written_by ?x0
  }