Which screenwriter that M1 , M2 , and M3 were influenced by was M4 's employee
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.writer .
?x0 ns:influence.influence_node.influenced M1 .
?x0 ns:influence.influence_node.influenced M2 .
?x0 ns:influence.influence_node.influenced M3 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M4
}