SELECT H.hacker_ID, H.name
FROM Submissions S
INNER JOIN Challenges C ON C.Challenge_ID = S.Challenge_ID
INNER JOIN Difficulty D ON D.Difficulty_Level = C.Difficulty_Level
INNER JOIN Hackers H ON H.hacker_ID = S.hacker_ID
WHERE S.Score = D.Score
GROUP BY H.hacker_ID, H.name
HAVING COUNT(S.Challenge_ID) > 1
ORDER BY COUNT(S.Challenge_ID) DESC, H.hacker_ID ASC;