static void Main(string[] args)
{
do
{
int n;
n = SoNguyen.NhapSoNguyenDuong("Nhap n = ");
Console.Write("Uoc so le cua so nguyen duong " + n + "\n");
TinhToan.lietke(n);
} while (SoNguyen.NhapSoNguyen("\nTiep tuc (1.Tiep, 0.Khong) ? ") != 0);
}