question: Was a male Canadian actor of M2 , M3 , and M4 a screenwriter
query: SELECT count(*) WHERE {
  ?x0 a ns:film.writer .
  ?x0 ns:film.actor.film/ns:film.performance.character M2 .
  ?x0 ns:film.actor.film/ns:film.performance.character M3 .
  ?x0 ns:film.actor.film/ns:film.performance.character M4 .
  ?x0 ns:people.person.gender ns:m.05zppz .
  ?x0 ns:people.person.nationality ns:m.0d060g
  }