I presume the problem has been simplified from an original case with meaningful keys in some meaningful order. Say the keys were dates in some odd format:

July 21,Milestone meeting
August 3,First walkthrough
August 3,Committee meeting
September 12,Second walkthrough
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merlyn puts all the values into a hash and then does a straight sort on the keys. That would make "August 3" come before "July 21" in my example. Rather than work out a fancy sorting routine for dates (or whatever the keys might be), my example maintains the original order of the first appearance of each key.