question: Which German art director was M1 's executive producer and writer
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.film_art_director .
  ?x0 ns:film.producer.films_executive_produced M1 .
  ?x0 ns:film.writer.film M1 .
  ?x0 ns:people.person.nationality ns:m.0345h
  }