TheatreSquareinthecapitalcityofBerlandhasarectangularshapewiththesizen × mmeters.Ontheoccasionofthecity'sanniversary,adecisionwastakentopavetheSquarewithsquaregraniteflagstones.Eachflagstoneisofthesizea × a.WhatistheleastnumberofflagstonesneededtopavetheSquare?It'sal