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

### Instruction:
who is the constructor when the laps is less than 68, the grid is more than 20 and the driver is thierry boutsen?

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

### Response:
SELECT Constructor FROM table WHERE Laps < 68 AND Grid > 20 AND Driver = thierry boutsen