dinamicArray

            string userInput = "";
            int[] array = new int[1];
            int[] tempArray;
            int numeric;
            int sum = 0;
            bool exit = true;

            while (exit)
            {
                userInput = Console.ReadLine();
                if (userInput == "exit")
                {
                    exit = false;
                }
                else if (userInput == "sum")
                {
                    for (int i = 0; i < array.Length; i++)
                    {
                        sum += array[i];
                    }
                    Console.WriteLine(sum);
                    sum = 0;
                }
                else
                {
                    numeric = Convert.ToInt32(userInput);
                    tempArray = new int[array.Length + 1];
                    for (int i = 0; i < array.Length; i++)
                    {
                        tempArray[i] = array[i];
                    }
                    tempArray[array.Length - 1] = numeric;
                    array = tempArray;
                }
            }