What is the vote number when immunity listed as David and reward is listed as none?
CREATE TABLE "table1_28742659_2" (
  "first_air_date" text,
  "reward" text,
  "immunity" text,
  "eliminated" text,
  "vote" text,
  "finish" text
);
SELECT "vote" FROM "table1_28742659_2" WHERE "immunity"='David' AND "reward"='None';