Which record has a result of loss in the Hero's 3 event?
CREATE TABLE "mixed_martial_arts_record" (
  "res" text,
  "record" text,
  "opponent" text,
  "method" text,
  "event" text,
  "round" real,
  "location" text
);
SELECT "record" FROM "mixed_martial_arts_record" WHERE "res"='loss' AND "event"='hero''s 3';