CREATE TABLE table_30180 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" FLOAT)

What is the production code of the episode written by Jeff Filgo?
SELECT MAX("Production code") FROM table_30180 WHERE "Written by" = 'Jeff Filgo'
SELECT MAX("Production code") FROM "table_30180" WHERE "Written by" = 'Jeff Filgo'