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

### Instruction:
Which Frequency MHz has an ERP W larger than 4, and a Call sign of w218ap?

### Inputs:
table_name: table, columns: ['Call sign', 'Frequency MHz', 'City of license', 'ERP W', 'FCC info']

### Response:
SELECT Frequency MHz FROM table WHERE ERP W > 4 AND Call sign = w218ap