Was a screenwriter a British actor that M2 was written by and M3 was written by
SELECT count(*) WHERE {
?x0 a ns:film.actor .
?x0 a ns:film.writer .
?x0 ns:film.writer.film M2 .
?x0 ns:film.writer.film M3 .
?x0 ns:people.person.nationality ns:m.07ssc
}