question: Was a person that M2 , M3 , and M4 were written by and M5 , M6 , and M7 starred a film producer
query: SELECT count(*) WHERE {
  ?x0 a ns:film.producer .
  ?x0 a ns:people.person .
  ?x0 ns:film.actor.film/ns:film.performance.film M5 .
  ?x0 ns:film.actor.film/ns:film.performance.film M6 .
  ?x0 ns:film.actor.film/ns:film.performance.film M7 .
  ?x0 ns:film.writer.film M2 .
  ?x0 ns:film.writer.film M3 .
  ?x0 ns:film.writer.film M4
  }