Did M2 and M3 star M0 's writer and star a screenwriter 's sibling
SELECT count(*) WHERE {
?x0 ns:film.writer.film M0 .
?x1 ns:people.person.sibling_s/ns:people.sibling_relationship.sibling|ns:fictional_universe.fictional_character.siblings/ns:fictional_universe.sibling_relationship_of_fictional_characters.siblings ?x2 .
?x2 a ns:film.writer .
FILTER ( ?x1 != ?x2 ) .
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
}