class Solution(object):
    def topKFrequent(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: List[int]
        """
        return [nn for nn, _ in collections.Counter(nums).most_common()][:k]
class Solution(object):
    def topKFrequent(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: List[int]
        """
        return [nn for nn, _ in collections.Counter(nums).most_common()][:k]
:type nums: List[int]         :type k: int         :rtype: List[int]