class CSet
    {
        private ArrayList ListData;
        public CSet()
        {
            ListData = new ArrayList();
        }
        public CSet(ArrayList newSetData)
        {
            ListData = new ArrayList();
            ListData.AddRange(newSetData);
        }
        public CSet(object[] items)
        {
            ListData = new ArrayList();
            ListData.AddRange(items);
        }
        public void Add(object item)
        {
            if (!ListData.Contains(item))
            {
                ListData.Add(item);
            }
        }
        public void AddRange(object[] item)
        {
            foreach (object i in item)
            {
                if (!ListData.Contains(i))
                {
                    ListData.Add(i);
                }
            }
        }
        public void Remove(object item)
        {
            if (ListData.Contains(item))
            {
                ListData.Remove(item);
            }
        }
        public int Size()
        {
            return ListData.Count;
        }
        public string SetAsString()
        {
            if (ListData.Count == 0)
            {
                return "[]";

            }
            else
            {
                string setOutput = "[";
                setOutput += ListData[0];
                for (int i = 1; i < ListData.Count; i++)
                {
                    setOutput = setOutput + ", " + ListData[i];
                }
                setOutput += "]";
                return setOutput;
            }
        }
        public bool IsInSet(object item)
        {
            return ListData.Contains(item);
        }
        public ArrayList Values
        {
            get { return ListData; }
            
        }
        public CSet Union(CSet setToAdd)
        {
            ArrayList addList = setToAdd.Values;
            CSet newSet = new CSet(addList);
            foreach (object o in ListData)
            {
                newSet.Add(o);
            }
            return newSet;
        }
        public CSet Difference(CSet setToSubtract)
        {
            ArrayList subList = setToSubtract.Values;
            CSet newSet = new CSet(ListData);
            foreach (object o in subList)
            {
                newSet.Remove(o);
            }
            return newSet;
        }
        public CSet Intersection(CSet setToIntersect)
        {
            CSet unionSet = Union(setToIntersect);
            CSet newSet = new CSet();
            ArrayList addList = unionSet.Values;
            foreach (object o in addList)
            {
                if (ListData.Contains(o) && setToIntersect.IsInSet(o))
                {
                    newSet.Add(o);
                }
            }
            return newSet;
        }

    
    
    }