import math
a, b = map(int, input().split())
g = math.gcd(abs(a), abs(b))
ans = 0
for x in range(10**2):
    for y in range(10**2):
        k = 2+g*(x+y)
        if k**k > 10**10:
            break
        ans += 10**6/k**k
print(ans/10**6)