If the episode was directed by Michael Offer, what was the episode number?
CREATE TABLE "table1_25084227_1" (
  "no" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_in_millions" text
);
SELECT MIN("no") FROM "table1_25084227_1" WHERE "directed_by"='Michael Offer';