user: Question: Which episode had bbc ranking and canle ranking of N/A?
Columns: ['Episode no.', 'Airdate', 'Viewers', 'BBC Three weekly ranking', 'Cable rank']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, '25 April 2013', '979,000', '2', '9']
SQL:

assistant: SELECT "Episode no." FROM "Table" WHERE "BBC Three weekly ranking" = 'N/A' AND "Cable rank" = 'N/A';