what is the minimum production code with title "foreign exchange problem / turn about"
CREATE TABLE "table1_10269427_3" (
  "episode_num" real,
  "production_code" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "airdate" text
);
SELECT MIN("production_code") FROM "table1_10269427_3" WHERE "title"='\"Foreign Exchange Problem / Turn About\"';