import math

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

a = abs(A)
b = abs(B)
d = math.gcd(a, b) if a != 0 or b != 0 else 0

if d == 0:
    print("{0:.12f}".format(0.25))
else:
    total = 0.0
    n = 0
    while True:
        s = 2 + d * n
        term = (n + 1) / (s ** s)
        if term < 1e-20:  # Break when term is negligible for precision
            break
        total += term
        n += 1
    # Ensure the output has enough decimal places
    print("{0:.12f}".format(total))