Condense Array

using System;
using System.Linq;

namespace CondenseArray
{
    class Program
    {
        static void Main(string[] args)
        {
            // 1. read array
            int[] originalArr = Console.ReadLine()
                .Split()
                .Select(int.Parse)
                .ToArray();
            int arrLenght = originalArr.Length;

            // 2. modifiedArr[i] = arr[i] + arr[i+1];
            while (arrLenght > 1)
            {
                int[] modifiedArr = new int[arrLenght];

                for (int i = 0; i < arrLenght - 1; i++)
                {
                    modifiedArr[i] = originalArr[i] + originalArr[i + 1];
                }

                originalArr = modifiedArr;
                arrLenght--;
            }
            // 3. cw(Result)
            Console.WriteLine(originalArr[0]);

        }
    }
}