int cmp(const void* a, const void* b){
    return *(int*)b - *(int*)a;
}
int lastStoneWeight(int* stones, int stonesSize){
    int i=0,val=stones[0];
    while(i<stonesSize-1)
    {
        i++;
        qsort(stones,stonesSize,sizeof(int),cmp);
        stones[0]-=stones[1];
        stones[1]=0;        
    }
    return stones[0];
}