C#: Calculate the sum of digits of N have 8 digits

/*  Enter an integer n has 8 digits. Take a look: 
- The total value of the digits 
- The value of the total unit 
- The average of the total   */
Source code:

class Program{

static void Main(){

            int n;

            Console.Write("Input n has 8 digits: ");

            n = int.Parse(Console.ReadLine());

            //The total value of the digits

            int s = 0;

            int balance;

            int first = n;

            while (n != 0) {

                balance = n % 10;

                s += balance;

                n /= 10;

            }

            //The value of the total unit

            int unit;

            unit = s % 10;

            //The average of the total

            double avg;

            avg = (double) s / 8;

            Console.WriteLine("The total value of the digits {0} is: {1}",first,s);

            Console.WriteLine("The value of the total unit {0} is: {1}",s,unit);

            Console.WriteLine("The average of the total {0} is: {1}",s,avg);

            Console.ReadLine();

        }

}