Condence

using System;
using System.Linq;

namespace ExamPreparation
{
    class Startup
    {
        static void Main()
        {
            int[] numbers = Console.ReadLine()
                .Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
                .Select(int.Parse)
                .ToArray();

            while (numbers.Length > 1)
            {
                int[] condensed = new int[numbers.Length - 1];

                for (int i = 0; i < numbers.Length - 1; i++)
                {
                    condensed[i] = numbers[i] + numbers[i + 1];
                }

                numbers = condensed;
            }

            Console.WriteLine(numbers[0]);
        }
    }
}