import math

A,B=map(int,input().split())

if A<0:A=-A
if B<0:B=-B
G=math.gcd(A,B)

if A==0 and B==0:
  print(0.25)
  exit(0)

ans=0
for n in range(10000):
  x=n+1
  y=2+n*G
  if y>1000000:break
  y=pow(y,y)
  ans+=x/y
  if x/y < 0.0000000001:break

print(ans)