/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.10.30 22:15:35
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    ll a,b;cin >> a >> b;
    a = abs(a);
    b = abs(b);
    ll g = __gcd(a,b);
    double ans = 0;
    for (int i = 0; i <= 10/g; i++) {
        ans += 1.0/pow(i*g+2,i*g+2)*(i+1);
    }
    printf("%.10f\n",ans);
    return 0;
}