import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = 10**9
# md = 998244353
md = 10**9+7

from math import gcd

a, b = LI()
g = gcd(a, b)
ans = 0
for i in range(500):
    x = 1+g*i
    if x > 500: break
    for j in range(500):
        y = 1+g*j
        if y > 500: break
        ans += 1/(x+y)**(x+y)

print("{:.7f}".format(ans))