11. Equal Sums

using System;
using System.Linq;

class InstructionSet_broken
{
    static void Main()
    {

        int[] arr = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();

        int arrsum = 0;
        bool isFound = false;
        if (arr.Length == 1)
        {
            Console.WriteLine("0");
        }
        else
        {
            for (int i = 0; i < arr.Length; i++)
            {
                arrsum += arr[i];
                int sum = 0;
                if (i == arr.Length-1 )
                {
                    break;
                }
                for (int j = arr.Length - 1; j >= 0; j--)
                {
                    sum += arr[j];
                    if (arrsum == sum)
                    {
                        Console.WriteLine(i + 1);
                        isFound = true;
                        break;
                    }
                    else if (arrsum < sum)
                    {
                        break;
                    }
                    if (isFound)
                    {
                        break;
                    }
                }
            }
            if (!isFound)
            {
                Console.WriteLine("no");
            }
        }

    }
}