Were M1 , M2 , and M3 directed by and written by a executive producer of a sequel of a film
SELECT count(*) WHERE {
?x0 ns:film.producer.films_executive_produced ?x1 .
?x1 ns:film.film.prequel ?x2 .
?x2 a ns:film.film .
M1 ns:film.film.directed_by ?x0 .
M1 ns:film.film.written_by ?x0 .
M2 ns:film.film.directed_by ?x0 .
M2 ns:film.film.written_by ?x0 .
M3 ns:film.film.directed_by ?x0 .
M3 ns:film.film.written_by ?x0
}