import math
import collections
class Solution(object):
    def maxDiff(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        res=0
        nums=collections.deque(nums)
        # print(nums)
        n=len(nums)
        for x in range(n-1):
            now=nums.popleft()
            xxx=list(nums)
            res=max(res,max(xxx)-now)
        # print(res)
        return res