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

### Instruction:
I want the lowest points diff for against being less than 578 and lost being 15 and points more than 26

### Inputs:
table_name: table, columns: ['Team', 'Played', 'Drawn', 'Lost', 'Against', 'Points Diff', 'Points']

### Response:
SELECT MIN Points Diff FROM table WHERE Against < 578 AND Lost = 15 AND Points > 26