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

### Instruction:
How many episodes have the title "the world of who"?

### Inputs:
table_name: table, columns: ['Episode #', 'Original airdate (UK)', 'Episode title', 'Doctor Who episode', 'Webcast link']

### Response:
SELECT COUNT Episode # FROM table WHERE Episode title = "The World of Who"