human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Season no., Series no., Title, Directed by, Written by, Original air date, Production code, U.S. Viewers (millions)
###Question: which is the  maximun serie episode number when the millions of North American spectators is 3.14?
gpt
SELECT MAX Series no. FROM table WHERE U.S. Viewers (millions) = 3.14