What is the class that that won 2 stages and has a position of DNF?
CREATE TABLE "dakar_rally_results" (
  "year" real,
  "class" text,
  "vehicle" text,
  "position" text,
  "stages_won" text
);
SELECT "class" FROM "dakar_rally_results" WHERE "stages_won"='2' AND "position"='dnf';