[Codewars] 099: Number of Proper Fractions with Denominator d
题目Ifnisthenumeratoranddthedenominatorofafraction,thatfractionisdefineda(reduced)properfractionifandonlyifGCD(n,d)==1.Forexample5/16isaproperfraction,while6/16isnot,asboth6and16aredivisibleby2,thusthef