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