CSLight #18

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

namespace CSLight
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] array = new int[0];
            bool isWorking = true;
            string input;

            while (isWorking)
            {
                Console.WriteLine("Введите число или команду: ");
                input = Console.ReadLine();
                switch(input)
                {
                    case "sum":
                        int sum = 0;

                        for (int x = 0; x < array.Length; x++)
                        {
                            sum += Convert.ToInt32(array[x]);
                        }

                        Console.WriteLine("\nСумма элементов = " + sum + "\n");
                        break;

                    case "exit":
                        isWorking = false;
                        break;

                    default:
                        int[] extendedArray = new int[array.Length + 1];
                        int element = Convert.ToInt32(input);

                        for (int x = 0; x < array.Length; x++)
                        {
                            extendedArray[x] = array[x];
                        }

                        extendedArray[extendedArray.Length - 1] = element;
                        array = extendedArray;
                        break;
                }
            }
        }
    }
}