CREATE TABLE table_29798 ("No ( s ) . in series" FLOAT, "No ( s ) . in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code ( s ) " FLOAT, "U.S. viewers  ( millions ) " TEXT)

What is the maximum production code of an episode written by Patty Lin?
SELECT MAX("Production code(s)") FROM table_29798 WHERE "Written by" = 'Patty Lin'
SELECT MAX("Production code(s)") FROM "table_29798" WHERE "Written by" = 'Patty Lin'