FUND_06.Equal Sums

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _11.Equal_Sums
{
    class Program
    {
        private static int pos = 0;
        private static bool isExist = false;
        static void Main(string[] args)
        {
            int[] arr = Console.ReadLine().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries).Select(int.Parse).ToArray();

            for (int i = 0; i < arr.Length; i++)
            {
                int leftSum = SumLeft(arr, i);
                int rightSum = SumRight(arr, i);
                if (leftSum == rightSum)
                {
                    Console.WriteLine(i);
                    return;
                }

            }
            Console.WriteLine("no");
        }

        private static int SumLeft(int[] arr, int position)
        {
            int leftSum = 0;

            for (int i = position; i > 0; i--)
            {
                int nextPosition = i - 1;
                if (i==0 )
                {
                    leftSum += 0;
                    break;
                }
                else
                {
                    leftSum += arr[nextPosition];

                }
            }
            return leftSum;

        }

        private static int SumRight(int[] arr, int position)
        {
            int rightSum = 0;

            for (int i = position; i < arr.Length; i++)
            {
                int nextPosition = (i +1 )%arr.Length;
                if (arr.Length == 1 || nextPosition == 0)
                {
                    rightSum += 0;

                    break;
                }
                else
                {
                    rightSum += arr[nextPosition];

                }
            }
            return rightSum;

        }
    }
}