Equal sum

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

namespace EqualSum
{
    class Program
    {


        static void Main(string[] args)
        {
            long[] input = Console.ReadLine().Split(new char[0], StringSplitOptions.RemoveEmptyEntries).Select(x => long.Parse(x)).ToArray();
            if (input.Length == 1)
            {
                Console.WriteLine(0); return;
            }

            else
            {

                for (int i = 0; i < input.Length; i++)
                {
                    long left = (input.Take(i).Sum());
                    long right = (input.Skip(i + 1).Sum());
                    if (left == right)
                    {
                        Console.WriteLine(i); return;
                    }

                }
            }
            Console.WriteLine("no");
        }
    }
}