static void Main(string[] args)
{
do
{
int a, b;
a = SoNguyen.NhapSoNguyenDuong("Nhap a = ");
b = SoNguyen.NhapSoNguyenDuong("Nhap b = ");
Console.Write("UCLN(" + a + "," + b + ") = " + TinhToan.ucln(a, b));
} while (SoNguyen.NhapSoNguyen("\nTiep tuc (1.Tiep, 0.Khong)") != 0);
}