CREATE TABLE table_name_24 (height__ft_ NUMBER, floors VARCHAR2, city VARCHAR2, height__m_ VARCHAR2)

What is the smallest height (ft) of a building in Frankfurt with a height (m) of 257 and less than 55 floors?
SELECT MIN(height__ft_) FROM table_name_24 WHERE city = "frankfurt" AND height__m_ = 257 AND floors < 55
SELECT MIN("height__ft_") FROM "table_name_24" WHERE "city" = "frankfurt" AND "floors" < 55 AND "height__m_" = 257