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

### Instruction:
What team were the bills playing where their first down was 23?

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

### Response:
SELECT Opponent FROM table WHERE Bills first downs = 23