# your code goes here
class Solution(object):
    def maxSum(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        stack = []
        for num in nums: 
            if num not in stack:
                stack.append(num)
 
        _sum = 0
        if len(stack) == 1:
            _sum = stack[0]
 
        elif max(stack) > 0: 
            for i in range(len(stack)):
                if _sum < _sum+stack[i]:
                    _sum += stack[i]
        else: 
            _sum = max(stack)
        return _sum
 
        return sum(stack)

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