def gcd(a,b):
    if b==0:
        return a
    else:
        return gcd(b,a%b)

a,b=map(int,input().split())
a=abs(a)
b=abs(b)
if a==0 and b==0:
    print(0.25)
elif a==0 or b==0:
    k=max(a,b)
    ans=0
    for x in range(1,20+1,k):
        for y in range(1,20+1,k):
            ans+=1/((x+y)**(x+y))
    print(ans)
else:
    g=gcd(a,b)
    a//=g
    b//=g
    ans=0.25
    for x in range(1,20+1,g):
        for y in range(1,20+1,g):
            if x==1 and y==1:
                continue
            if (a+b)%2==0:
                if (x+y)%2==0:
                    ans+=1/((x+y)**(x+y))
            else:
                ans+=1/((x+y)**(x+y))
    print(ans)