question: Did M1 employ M2 , M2 , and M3 , employ M4 and M5 , and employ a art director 's sibling
query: SELECT count(*) WHERE {
  ?x0 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 ?x1 .
  ?x1 a ns:film.film_art_director .
  FILTER ( ?x0 != ?x1 ) .
  M1 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
  M1 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
  M1 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
  M1 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
  M1 ns:business.employer.employees/ns:business.employment_tenure.person M4 .
  M1 ns:business.employer.employees/ns:business.employment_tenure.person M5
  }