Who directed episode number 626 in the series?
CREATE TABLE "season_20_1974_75" (
  "series_num" real,
  "season_num" real,
  "title" text,
  "director" text,
  "writer_s" text,
  "airdate" text
);
SELECT "director" FROM "season_20_1974_75" WHERE "series_num"=626;