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

### Instruction:
Which Grid has Laps of 24, and a Rider of marco melandri?

### Inputs:
table_name: table, columns: ['Rider', 'Manufacturer', 'Laps', 'Time', 'Grid']

### Response:
SELECT SUM Grid FROM table WHERE Laps = 24 AND Rider = marco melandri