question: What Mexican writer of a film was M1 's director
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:film.director.film M1 .
  ?x0 ns:film.writer.film ?x1 .
  ?x0 ns:people.person.nationality ns:m.0b90_r .
  ?x1 a ns:film.film
  }