What is the sum of Game, when High Points is "D. McKey (24)", and when Team is "@ Dallas Mavericks"?
CREATE TABLE "game_log" (
  "game" real,
  "date" text,
  "team" text,
  "score" text,
  "high_points" text,
  "high_rebounds" text,
  "high_assists" text,
  "location_attendance" text,
  "record" text
);
SELECT SUM("game") FROM "game_log" WHERE "high_points"='d. mckey (24)' AND "team"='@ dallas mavericks';