Was M4 executive produced by a person that directed M1 , M2 , and M3
SELECT count(*) WHERE {
?x0 a ns:people.person .
?x0 ns:film.director.film M1 .
?x0 ns:film.director.film M2 .
?x0 ns:film.director.film M3 .
M4 ns:film.film.executive_produced_by ?x0
}