Was a person that M1 was edited by and starred M2 's editor and art director
SELECT count(*) WHERE {
?x0 a ns:people.person .
?x0 ns:film.actor.film/ns:film.performance.film M1 .
?x0 ns:film.editor.film M1 .
?x0 ns:film.editor.film M2 .
?x0 ns:film.film_art_director.films_art_directed M2
}