using System;

​

public class Program

{

    public static void Main()

    {

        int[] arry1 = new int[4]{1, 20, 2, 10};

        int rotate = 0;

        int sum = 0;

        int sumfinal = 0;

        Console.WriteLine("Enter number of rotations");

        var cons = arry1.Length - 1;

        while (rotate < Convert.ToInt32(cons))

        {

            var first = arry1[0];

            for (int i = 0; i < arry1.Length; i++)

            {

                if (i != arry1.Length - 1)

                {

                    arry1[i] = arry1[i + 1];

                }

                else

                {

                    arry1[arry1.Length - 1] = first;

                }

            }

​

            for (int a = 0; a < arry1.Length; a++)

            {

                sum = a * arry1[a] + sum;

            }

​

            if (sumfinal < sum)

            {

                sumfinal = sum;

            }

​

            sum = 0;

            rotate++;

        }

​

        Console.WriteLine(sumfinal);

    }

}