What was the minimum number of the episode that first aired August 11?
CREATE TABLE "table1_25691838_8" (
  "episode_num" real,
  "the_w_rd" text,
  "guest" text,
  "introductory_phrase" text,
  "original_airdate" text,
  "production_code" real
);
SELECT MIN("episode_num") FROM "table1_25691838_8" WHERE "original_airdate"='August 11';