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

### Instruction:
How many episodes had a production code of 5m13?

### Inputs:
table_name: table, columns: ['Ep.', 'Season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Prod. Code']

### Response:
SELECT COUNT Ep. FROM table WHERE Prod. Code = 5M13