Were M1 and M3 employed by M2 and employed by a screenwriter 's sibling 's country of nationality
SELECT count(*) WHERE {
?x0 ^ns:people.person.nationality ?x1 .
?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 ) .
M1 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
M1 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company M2
}