Name the series number directed by richard thorpe written by dee johnson
CREATE TABLE "table1_17355579_1" (
  "series_num" real,
  "season_num" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text
);
SELECT MAX("series_num") FROM "table1_17355579_1" WHERE "directed_by"='Richard Thorpe' AND "written_by"='Dee Johnson';