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_50 (quantity VARCHAR, railway_number_s_ VARCHAR)
### Question:
What is the quantity for railway 263?
### Answer:
SELECT quantity FROM table_name_50 WHERE railway_number_s_ = "263"