using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter a number between 100 and 999:");

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

        int div = num / 10;

        int remainder = num % 10;

        remainder = remainder + (div % 10);

        div = div / 10;

        Console.WriteLine();

        Console.WriteLine("The sum of the number's three digits are: {0}", div + remainder);    

​

    }

}

/*      Console.WriteLine("Enter number between 100 and 999");

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

        int first = num / 100;

        int middle = num / 10 % 10;

        int last = num % 10;

        Console.WriteLine(first + middle + last);                       */