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

### Instruction:
What constructor has a grid less than 21, and time/retired of engine?

### Inputs:
table_name: table, columns: ['Driver', 'Entrant', 'Constructor', 'Time/Retired', 'Grid']

### Response:
SELECT Constructor FROM table WHERE Grid < 21 AND Time/Retired = engine