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

### Instruction:
When is the latest game the bills had 21 first downs

### Inputs:
table_name: table, columns: ['Game', 'Date', 'Opponent', 'Result', 'Bills points', 'Opponents', 'Bills first downs', 'Record']

### Response:
SELECT MIN Game FROM table WHERE Bills first downs = 21