class Solution:
    def longestConsecutive(self, nums):

        if not nums:
            return 0

        nums.sort()
        longest_streak = 0
        current_streak = 1

        for index, num in enumerate(nums[:-1]):
            # an important step here would be to avoid duplicates
            if (nums[index] != nums[index+1]):
                if (nums[index] + 1 == nums[index+1]):
                    current_streak += 1
                else:
                    longest_streak = max(current_streak, longest_streak)
                    current_streak = 1

        # very important step here since there could be cases
        # where current streak could be every increasing and
        # longest streak could not get a chance to be assigned
        longest_streak = max(current_streak, longest_streak)

        return longest_streak