Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_19 (railway_number_s_ VARCHAR, quantity VARCHAR)
### Question:
Which railway number has 3 quantity?
### Answer:
SELECT railway_number_s_ FROM table_name_19 WHERE quantity = 3