question: Did M1 and M3 influence a screenwriter and influence M2
query: SELECT count(*) WHERE {
  ?x0 a ns:film.writer .
  M1 ns:influence.influence_node.influenced ?x0 .
  M1 ns:influence.influence_node.influenced M2 .
  M3 ns:influence.influence_node.influenced ?x0 .
  M3 ns:influence.influence_node.influenced M2
  }