python very simple solution 95% fast
```\nclass Solution(object):\n    def lastStoneWeight(self, stones):\n        """\n        :type stones: List[int]\n        :rtype: int\n        """\n        \n
```\nclass Solution(object):\n    def lastStoneWeight(self, stones):\n        """\n        :type stones: List[int]\n        :rtype: int\n        """\n        \n        while len(stones) > 1:\n            stones.sort()\n            x, y = stones[-2], stones[-1]\n            stones = stones[:-2]\n       \n            if x != y:\n                stones.append(y - x)\n                \n        return stones[0] if stones else 0
['Python']