Put these six on the balance, three on each side, and then take one from each side. If the result is the same weight, then the one just removed is heavy. Just weigh the two just removed, and you will know which one to take. If one side is still heavy after removing each one, remove one from each side. If the result is the same weight, one of the two taken out for the second time is heavy. Just weigh the removed two for the second time and you will know which one is heavier. If you remove one each for the second time, the remaining results have been sorted out, and you can directly know which one is heavier.