import java.util.regex.*;

class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Pattern p = Pattern.compile("(.*?as .*?)(,|$)", Pattern.CASE_INSENSITIVE );
		String query = "f.id AS id, CONCAT(a1.id, a2.id, a3.id) AS cnp, SUM(A3.nr) AS sum";
		Matcher m = p.matcher( query );
		while ( m.find() ){
			System.out.println( m.group(1) );
		}
	}
}