CREATE TABLE table_29661 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Prod. code" FLOAT, "U.S. viewers  ( millions ) " TEXT)

What is the maximum production code of the episode directed by Sean McNamara?
SELECT MAX("Prod. code") FROM table_29661 WHERE "Directed by" = 'Sean McNamara'
SELECT MAX("Prod. code") FROM "table_29661" WHERE "Directed by" = 'Sean McNamara'