Was a American star of a prequel of M2 M1 's director
SELECT count(*) WHERE {
?x0 ns:film.actor.film/ns:film.performance.film ?x1 .
?x0 ns:film.director.film M1 .
?x0 ns:people.person.nationality ns:m.09c7w0 .
?x1 ns:film.film.sequel M2
}