Who directed series #4 that was teleplayed by David Simon?
CREATE TABLE "table1_14346353_1" (
  "series_num" real,
  "title" text,
  "story_by" text,
  "teleplay_by" text,
  "directed_by" text,
  "original_air_date" text
);
SELECT COUNT("directed_by") FROM "table1_14346353_1" WHERE "teleplay_by"='David Simon' AND "series_num"=4;