Were M3 , M4 , M5 , and M6 influenced by a person and influenced by a Mexican screenwriter
SELECT count(*) WHERE {
?x0 a ns:film.writer .
?x0 ns:people.person.nationality ns:m.0b90_r .
?x1 a ns:people.person .
M3 ns:influence.influence_node.influenced_by ?x0 .
M3 ns:influence.influence_node.influenced_by ?x1 .
M4 ns:influence.influence_node.influenced_by ?x0 .
M4 ns:influence.influence_node.influenced_by ?x1 .
M5 ns:influence.influence_node.influenced_by ?x0 .
M5 ns:influence.influence_node.influenced_by ?x1 .
M6 ns:influence.influence_node.influenced_by ?x0 .
M6 ns:influence.influence_node.influenced_by ?x1
}