n,k=map(int,input().split()) s1=n*(n+1)/2 s2=0 d=0 for i in range(k,n+1): if i%k==0: s2+=i d+=1 t1=s2/d t2=(s1-s2)/(n-d) print('{0:.1f},{1:.1f}'.format(t1,t2 ) )