What is the highest number of points the cosworth straight-4 engine scored?
CREATE TABLE "complete_formula_one_world_championship_" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "pts" real
);
SELECT MAX("pts") FROM "complete_formula_one_world_championship_" WHERE "engine"='cosworth straight-4';