CREATE TABLE table_24456 ("No." FLOAT, "#" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "U.S. viewers  ( million ) " TEXT, "Original air date" TEXT, "Production code" FLOAT)

Name the total number of production code for episode by steve cohen & andrew dettman
SELECT COUNT("Production code") FROM table_24456 WHERE "Written by" = 'Steve Cohen & Andrew Dettman'
SELECT COUNT("Production code") FROM "table_24456" WHERE "Written by" = 'Steve Cohen & Andrew Dettman'