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