What was the first prize for the FTOPS XIII series with more than 5,291 entrants?
CREATE TABLE "ftops_main_event_winners" (
  "series" text,
  "date" text,
  "entrants" real,
  "winner" text,
  "first_prize" text
);
SELECT "first_prize" FROM "ftops_main_event_winners" WHERE "entrants">'5,291' AND "series"='ftops xiii';