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

### Instruction:
What round was a loss with a record of 12-3?

### Inputs:
table_name: table, columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round']

### Response:
SELECT Round FROM table WHERE Res. = loss AND Record = 12-3