question: Was M1 's Mexican parent 's child M2
query: SELECT count(*) WHERE {
  ?x0 ns:people.person.children|ns:fictional_universe.fictional_character.children|ns:organization.organization.child/ns:organization.organization_relationship.child M1 .
  ?x0 ns:people.person.nationality ns:m.0b90_r .
  M2 ns:people.person.parents|ns:fictional_universe.fictional_character.parents|ns:organization.organization.parent/ns:organization.organization_relationship.parent ?x0
  }