What person that influenced M1 and M2 was a American director of M4 , M5 , and M6
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:film.director.film M4 .
?x0 ns:film.director.film M5 .
?x0 ns:film.director.film M6 .
?x0 ns:influence.influence_node.influenced M1 .
?x0 ns:influence.influence_node.influenced M2 .
?x0 ns:people.person.nationality ns:m.09c7w0
}