Was a film 's prequel 's American male writer M1
SELECT count(*) WHERE {
?x0 ns:film.film.sequel ?x1 .
?x1 a ns:film.film .
M1 ns:film.writer.film ?x0 .
M1 ns:people.person.gender ns:m.05zppz .
M1 ns:people.person.nationality ns:m.09c7w0
}