private void btnTulosta_Click(object sender, RoutedEventArgs e)
        {

            int[] luvut = { 15, 4, 68, 23, 22, 7, 15, 10, 32, 15 };

            int summa = 0;

            for ( int i = 0; i <= luvut.Length; i++)
            {
                luvut[i] =+ summa;
            }

            txbTulosta.Text = summa.ToString();

        }