static void Main(string[] args)
        {
            int[] arr = { 1, 2, 3, -4, 5, 6, 7, 8, 9, 10 };
            Change(arr);


            Console.ReadKey();

        }
        public static void Change(int[] array)
        {
            int sign = array[0];
            int a = -1;
            for (int i = 0; i < array.Length; i++)
            {
                if (array[i] > 0)
                {
                    Console.WriteLine(a * array[i]);
                }
                else
                {
                    Console.WriteLine(a