import "sort"
func lastStoneWeight(stones []int) int {
for len(stones) > 1 {
sort.Ints(stones)
n := stones[len(stones)-1] - stones[len(stones)-2]
stones = stones[:len(stones)-2]
if n != 0 {
stones = append(stones, n)
}
}
if len(stones) == 1 {
return stones[0]
}
return 0
}