Did M1 , M2 , and M3 direct M0 's prequel 's prequel
SELECT count(*) WHERE {
?x0 ns:film.film.sequel ?x1 .
?x1 ns:film.film.sequel M0 .
M1 ns:film.director.film ?x0 .
M2 ns:film.director.film ?x0 .
M3 ns:film.director.film ?x0
}