SELECT CONCAT(FINAL_TABLE.H_ID, " ", HACKERS.NAME) AS result
FROM HACKERS
JOIN (
    SELECT Submissions.HACKER_ID AS H_ID, COUNT(*) AS MAXSCORE_COUNT
    FROM Submissions
    JOIN (
        SELECT CHALLENGES.CHALLENGE_ID AS C_ID, DIFFICULTY.SCORE AS MAX_SCORE
        FROM CHALLENGES
        INNER JOIN DIFFICULTY ON CHALLENGES.DIFFICULTY_LEVEL = DIFFICULTY.DIFFICULTY_LEVEL
    ) AS MAX_TABLE ON MAX_TABLE.C_ID = Submissions.CHALLENGE_ID
    WHERE SUBMISSIONS.SCORE = MAX_TABLE.MAX_SCORE
    GROUP BY Submissions.HACKER_ID
    HAVING MAXSCORE_COUNT > 1 -- Filter hackers who achieved full scores for more than one challenge
) AS FINAL_TABLE ON FINAL_TABLE.H_ID = HACKERS.HACKER_ID
ORDER BY FINAL_TABLE.MAXSCORE_COUNT DESC, HACKERS.NAME;