text: --  Author: Zoltan Viski (vizoli)
  --          vizoli.hu
  --          github.com/zoltanviski
  --          hackerrank.com/zoltanviski
  
  -- Problem: https://www.hackerrank.com/challenges/asian-population
  
  SELECT SUM(CITY.POPULATION) 
  FROM CITY, COUNTRY
  WHERE CITY.COUNTRYCODE = COUNTRY.CODE 
        AND COUNTRY.CONTINENT = 'Asia';