Were M2 and M3 directed by a Mexican executive producer of M1 's sequel
SELECT count(*) WHERE {
?x0 ns:film.producer.films_executive_produced ?x1 .
?x0 ns:people.person.nationality ns:m.0b90_r .
?x1 ns:film.film.prequel M1 .
M2 ns:film.film.directed_by ?x0 .
M3 ns:film.film.directed_by ?x0
}