class Solution:
    def lastStoneWeight(self, stones: List[int]) -> int:

        stones = [-s for s in stones]
        heapq.heapify(stones)

        while (len(stones) > 1):
            x = heapq.heappop(stones)
            y = heapq.heappop(stones)
            if x!=y :
                heapq.heappush(stones, x - y)

        return -stones[0] if len(stones) > 0 else 0