question: Did a film producer 's sibling direct M1 's prequel
query: SELECT count(*) WHERE {
  ?x0 ns:film.director.film ?x1 .
  ?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 ?x2 .
  ?x1 ns:film.film.sequel M1 .
  ?x2 a ns:film.producer .
  FILTER ( ?x0 != ?x2 )
  }