How many weeks have an Opponent of at san francisco 49ers, and an Attendance smaller than 34,354?
CREATE TABLE "schedule" (
  "week" real,
  "date" text,
  "opponent" text,
  "result" text,
  "attendance" real
);
SELECT COUNT("week") FROM "schedule" WHERE "opponent"='at san francisco 49ers' AND "attendance"<'34,354';