Goodwill acquired in a business combination is initially measured at cost. Following initial recognition, goodwill is measured at cost less accumulated impairment losses. Goodwill is reviewed for impairment annually or more frequently if events and circumstances indicate that the carrying value may be impaired. For the purpose of impairment testing, goodwill acquired in a business combination is, from the acquisition date,allocated to each of the Group’s cash-generating units, or groups of cash-generating units, that are expected to benefit from the synergies of the combination, irrespective of whether other assets or liabilities of the acquire are assigned to those units or groups of units