Did M2 and M3 star a actor of M0 and star a film producer
SELECT count(*) WHERE {
?x0 ns:film.actor.film/ns:film.performance.character M0 .
?x1 a ns:film.producer .
M2 ns:film.film.starring/ns:film.performance.actor ?x0 .
M2 ns:film.film.starring/ns:film.performance.actor ?x1 .
M3 ns:film.film.starring/ns:film.performance.actor ?x0 .
M3 ns:film.film.starring/ns:film.performance.actor ?x1
}