How many episodes are directed by ricardo mendez matta?
CREATE TABLE "table1_26866519_1" (
  "series_num" real,
  "season_num" real,
  "title" text,
  "director" text,
  "writer" text,
  "original_airdate" text
);
SELECT COUNT("season_num") FROM "table1_26866519_1" WHERE "director"='Ricardo Mendez Matta';