question: What did M0 and M1 executive produce and a person executive produce
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:film.film.executive_produced_by ?x1 .
  ?x0 ns:film.film.executive_produced_by M0 .
  ?x0 ns:film.film.executive_produced_by M1 .
  ?x1 a ns:people.person
  }