Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Which episode had bbc ranking and canle ranking of n/a?

### Inputs:
table_name: table, columns: ['Episode no.', 'Airdate', 'Viewers', 'BBC Three weekly ranking', 'Cable rank']

### Response:
SELECT COUNT Episode no. FROM table WHERE BBC Three weekly ranking = N/A AND Cable rank = N/A