public static Set operator +(Set ob, char ch)
        {
            if(ob.find(ch) != -1)
            {
                return new Set(ob);
            }
            else
            {

                Set newset = new Set(ob.Length + 1);

                for(int i = 0; i < ob.Length; i++)
                newset.members[i] = ob.members[i];

                newset.Length = ob.Length + 1;

                newset.members[newset.Length - 1] = ch;

                return newset;
            }
        }
        public static Set operator +(Set ob1, Set ob2)
        {
            Set newset = new Set(ob1);

            for(int i =0; i < ob2.Length; i++)
            newset = newset + ob2[i];

            return newset;
        }
        public static Set operator -(Set ob, char ch)
        {
            Set newset = new Set();

            int i = ob.find(ch);

            for(int j =0; j < ob.Length; j++)
            if(j != i) newset = newset + ob.members[j];

            return newset;
        }
 public Set(Set s)
 {
     members = new char[s.Length];
     for(int i=0; i < s.Length; i++) members[i] = s.members[i];
     Length = s.Length;
 }
        public static void SetDemoStart()
        {
            Set s1 = new Set();
            Set s2 = new Set();
            Set s3 = new Set();

            s1 = s1 + 'A';
            s1 = s1 + 'B';
            s1 = s1 + 'C';

            Console.Write("s1 after adding A B C: ");
            for(int i=0; i<s1.Length; i++)
            Console.Write(s1[i] + " ");
            Console.WriteLine();

            s1 = s1 - 'B';
            Console.Write("s1 after s1 = s1 - 'B': ");
            for(int i=0; i<s1.Length; i++)
            Console.Write(s1[i] + " ");
            Console.WriteLine();

            s1 = s1 - 'A';
            Console.Write("s1 after s1 = s1 - 'A': ");
            for(int i=0; i<s1.Length; i++)
            Console.Write(s1[i] + " ");
            Console.WriteLine();

            s1 = s1 - 'C';
            Console.Write("s1 after s1 = s1 - 'C': ");
            for(int i=0; i<s1.Length; i++)
            Console.Write(s1[i] + " ");
            Console.WriteLine("\n");

            s1 = s1 + 'A';
            s1 = s1 + 'B';
            s1 = s1 + 'C';
            Console.Write("s1 after adding A B C: ");
            for(int i=0; i<s1.Length; i++)
            Console.Write(s1[i] + " ");
            Console.WriteLine();

            s2 = s2 + 'A';
            s2 = s2 + 'X';
            s2 = s2 + 'W';

            Console.Write("s2 after adding A X W: ");
            for(int i=0; i<s2.Length; i++)
            Console.Write(s2[i] + " ");
            Console.WriteLine();

            s3 = s1 + s2;
            Console.Write("s3 after s3 = s1 + s2: ");
            for(int i=0; i<s3.Length; i++)
            Console.Write(s3[i] + " ");
            Console.WriteLine();

            s3 = s3 - s1;
            Console.Write("s3 after s3 - s1: ");
            for(int i=0; i<s3.Length; i++)
            Console.Write(s3[i] + " ");
            Console.WriteLine("\n");

            Console.WriteLine();

            s2 = s2 - s2;
            s2 = s2 + 'C';
            s2 = s2 + 'B';
            s2 = s2 + 'A';

            s1 = s1 + 'D';
            s1 = s1 + 'E';
            s2 = s2 + 'E';

            Console.Write("s1 is now: ");
            for(int i=0; i<s1.Length; i++)
            Console.Write(s1[i] + " ");
            Console.WriteLine();

            Console.Write("s2 is now: ");
            for(int i=0; i<s2.Length; i++)
            Console.Write(s2[i] + " ");
            Console.WriteLine();

            Console.Write("s3 is now: ");
            for(int i=0; i<s3.Length; i++)
            Console.Write(s3[i] + " ");
            Console.WriteLine();

            Console.WriteLine();
        }