How many writers were there in the episode directed by Charles Haid?
CREATE TABLE "table1_23255941_1" (
  "episode_num" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "viewers_in_millions" text
);
SELECT COUNT("written_by") FROM "table1_23255941_1" WHERE "directed_by"='Charles Haid';