'Limit INT OFFSET @variable' throw runtime error in mysql server

I'm trying to solve this problem in Hackerrand The problem asks for the median in a specific column my code: SET @VAE = (SELECT COUNT(*) FROM STATION); SET @VAE1 = ROUND(@VAE/2)-1; SELECT LAT_N FROM STATION ORDER BY LAT_N LIMIT @VAE1; But I get syntax error. When I write the query as following it runs ok, but I don't want it in such way SET @VAE = (SELECT COUNT(*) FROM STATION); SET @VAE1 = ROUND(@VAE/2)-1; SELECT LAT_N FROM STATION ORDER BY LAT_N LIMIT 5; what is the problem ?