question: Which screenwriter that influenced M1 , M2 , and M3 and influenced M4 was M6 's Canadian parent
query: 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:influence.influence_node.influenced M4 .
  ?x0 ns:people.person.children|ns:fictional_universe.fictional_character.children|ns:organization.organization.child/ns:organization.organization_relationship.child M6 .
  ?x0 ns:people.person.nationality ns:m.0d060g
  }