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

### Instruction:
Which railway number has 3 quantity?

### Inputs:
table_name: table, columns: ['Class', 'Railway number(s)', 'DRG number(s)', 'Quantity', 'Year(s) of manufacture', 'Axle arrangement ( UIC ) Bauart']

### Response:
SELECT Railway number(s) FROM table WHERE Quantity = 3