question: Were M2 and M5 written by M3 and M4 and written by a American star of M1 's sequel
query: SELECT count(*) WHERE {
  ?x0 ns:film.actor.film/ns:film.performance.film ?x1 .
  ?x0 ns:people.person.nationality ns:m.09c7w0 .
  ?x1 ns:film.film.prequel M1 .
  M2 ns:film.film.written_by ?x0 .
  M2 ns:film.film.written_by M3 .
  M2 ns:film.film.written_by M4 .
  M5 ns:film.film.written_by ?x0 .
  M5 ns:film.film.written_by M3 .
  M5 ns:film.film.written_by M4
  }