int i;
            bool simetric=true;
            int[] vec = { 1, 2, 5, 7, 7, 5, 2, 1 };
            for (i = 0; i < vec.Length / 2; i++)
                if (vec[i] != vec[vec.Length - 1 - i])
                {
                    simetric = false;
                    i = vec.Length;
                }
            if (simetric == true)
                Console.WriteLine("yes");
            else
                Console.WriteLine("no");
            Console.ReadLine();