Name the least week for  l 26–42
CREATE TABLE "table1_26401898_2" (
  "week" real,
  "date" text,
  "kickoff" text,
  "opponent" text,
  "final_score" text,
  "team_record" text,
  "game_site" text,
  "attendance" real
);
SELECT MIN("week") FROM "table1_26401898_2" WHERE "final_score"='L 26–42';