using System;

​

class Program

{

    static void Main()

    {

        Console.WriteLine("Enter a 4 digit number:");

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

​

        int a = num / 1000;

        int b = (num / 100) % 10;

        int c = (num / 10) % 10;

        int d = num % 10;

​

        int dcba = d * 1000 + c * 100 + b * 10 + a;

        int acbd = a * 1000 + c * 100 + b * 10 + d;

        int sum = a + b + c + d;

        int product = (d*10 + a) * (c * 10 + b);

​

        Console.WriteLine("DCBA = " + dcba);

        Console.WriteLine("ACBD = " + acbd);

        Console.WriteLine("Sum of digits (A + B + C + D) = " + sum);

        Console.WriteLine("Product of DA and CB = " + product);

    }

}

​