What is the total number in the season for the #30 Robert Berlinger series?
CREATE TABLE "season_2" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text
);
SELECT COUNT("no_in_season") FROM "season_2" WHERE "directed_by"='robert berlinger' AND "no_in_series"=30;