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

### Instruction:
Which Laps have a Time/Retired of + 4 laps, and a Grid larger than 18?

### Inputs:
table_name: table, columns: ['Driver', 'Team', 'Laps', 'Time/Retired', 'Grid', 'Points']

### Response:
SELECT AVG Laps FROM table WHERE Time/Retired = + 4 laps AND Grid > 18