Writer Max Ehrlich, what is the minimum series number?
CREATE TABLE "table1_19852975_4" (
  "series_num" real,
  "season_num" real,
  "title" text,
  "director_s" text,
  "writer_s" text,
  "airdate" text,
  "production_code" real,
  "arties_disguises" text
);
SELECT MIN("series_num") FROM "table1_19852975_4" WHERE "writer_s"='Max Ehrlich';