static void Main()
        {
            Num();
        }
        public static void Num()
        {
            int[] four = new int[7];
            Console.Write("Enter a 7 digit number: ");
            int n = int.Parse(Console.ReadLine());
            for (int i = 6; i >= 0; i--)
            {
                four[i] = n % 10;
                n /= 10;
            }
            Console.WriteLine("The 4th digit is " + four[3]);

        }