CREATE TABLE table_22580855_1 (series_no INT, us_viewers__millions_ VARCHAR)

which is the maximun serie episode number when the millions of North American spectators is 3.14?
SELECT MAX(series_no) FROM table_22580855_1 WHERE us_viewers__millions_ = "3.14"
SELECT MAX("series_no") FROM "table_22580855_1" WHERE "3.14" = "us_viewers__millions_"