static void Main(string[] args)
{
do
{
int n;
n = SoNguyen.NhapSoNguyenDuong("Nhap n=");
if (TinhToan.ktdx(n))
{
Console.Write(n + " la so doi xung");
}
else
{
Console.Write(n + " khong la so doi xung");
}
} while (SoNguyen.NhapSoNguyen("\nTiep tuc (1.Tiep, 0.Khong)") != 0);
}