What is the quantity for railway 263?
CREATE TABLE table_name_50 (quantity VARCHAR, railway_number_s_ VARCHAR)
SELECT quantity FROM table_name_50 WHERE railway_number_s_ = "263"
### 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"