incorrect check

I would like to give some feedback about ...

I was trying to check the solution which i think works but the system does not recognize it - it keeps comparing my solution to solution with alternative initial list every time i press "check" so that they never match... please advise

Solution: nums = [1,2,2,3,3,4,6,6,6,7,8,5,9] Xnums = [x for x in nums if nums.count(x)>1]

From: http://www.checkio.org/mission/non-unique-elements/solve/

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