What is the production number of 3-04?
CREATE TABLE "table1_25046766_3" (
  "episode_no" text,
  "prod_no" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_airdate_uk" text
);
SELECT MAX("prod_no") FROM "table1_25046766_3" WHERE "episode_no"='3-04';