from math import *

A, B = map(int, input().split())
A, B = abs(A), abs(B)
ans = 0.25
if A == B == 0:
    print(ans)
else:
    g = gcd(A, B)
    ans = 0
    A, B = A // g, B // g
    flag = (A % 2 == B % 2)
    for i in range(30):
        for j in range(30):
            if i % g == j % g == 0:
                if flag:
                    if (i//g) % 2 != (j//g) % 2:
                        continue
                ans += 1/((i + j + 2) ** (i + j + 2))
    print(ans)