question: Was a director of M2 and M3 a American executive producer of M0
query: SELECT count(*) WHERE {
  ?x0 ns:film.director.film M2 .
  ?x0 ns:film.director.film M3 .
  ?x0 ns:film.producer.films_executive_produced M0 .
  ?x0 ns:people.person.nationality ns:m.09c7w0
  }