#include "bits/stdc++.h"
using namespace std;
using     ll=long long;
using    vll=vector<   ll>;
using   vvll=vector<  vll>;
using  vvvll=vector< vvll>;
using vvvvll=vector<vvvll>;
using     dd=double;
using    vdd=vector<   dd>;
using   vvdd=vector<  vdd>;
using pll=pair<ll,ll>; using tll=tuple<ll,ll,ll>; using qll=tuple<ll,ll,ll,ll>;
using   vpll=vector<  pll>;

constexpr ll INF = 1LL << 60;
struct Fast{ Fast(){ cin.tie(0); ios::sync_with_stdio(false); cout<<fixed<<setprecision(numeric_limits<double>::max_digits10); } } fast;
#define REPS(i, S, E) for (ll i = (S); i <= (E); i++)
#define REP(i, N) REPS(i, 0, (N)-1)
#define DEPS(i, S, E) for (ll i = (E); i >= (S); i--)
#define DEP(i, N) DEPS(i, 0, (N)-1)
#define rep(i, S, E)  for (ll i = (S); i <= (E); i++)
#define dep(i, E, S)  for (ll i = (E); i >= (S); i--)
#define each(e, v) for (auto&& e : v)
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
template<class T> inline bool chmax(T &a, T b) { if (a < b) { a = b; return true; }return false; }
template<class T> inline bool chmin(T &a, T b) { if (a > b) { a = b; return true; }return false; }
template<class T> inline T MaxE(vector<T>&v,ll S,ll E){ T m=v[S]; rep(i,S,E)chmax(m,v[i]); return m; }
template<class T> inline T MinE(vector<T>&v,ll S,ll E){ T m=v[S]; rep(i,S,E)chmin(m,v[i]); return m; }
template<class T> inline T MaxE(vector<T> &v) { return MaxE(v,0,(ll)v.size()-1); }
template<class T> inline T MinE(vector<T> &v) { return MinE(v,0,(ll)v.size()-1); }
template<class T> inline T Sum(vector<T> &v,ll S,ll E){ T s=T(); rep(i,S,E)s+=v[i]; return s; }
template<class T> inline T Sum(vector<T> &v) { return Sum(v,0,v.size()-1); }
template<class T> inline ll sz(T &v){ return (ll)v.size(); }
inline ll CEIL(ll a,ll b){ return (a<0) ? -(-a/b) : (a+b-1)/b; }
inline ll FLOOR(ll a,ll b){ return -CEIL(-a,b); }



#if 0
#include <atcoder/all>
using namespace atcoder;
#endif


template<class T> inline T POW(T a,ll n){ T r=1; for (; n>0; n>>=1,a*=a){ if (n&1)r*=a; } return r; }
inline ll POW(int a,ll n){ return POW((ll)a,n); }


void solve()
{
	ll A,B;  cin >> A >> B;
	A=abs(A);
	B=abs(B);
	if (A>B){
		swap(A,B);
	}

	ll g=gcd(A,B);
	ll a=A/g;
	ll b=B/g;
	bool isn=false;
	if (a%2==1 and b%2==1){
		isn=true;
	}

	dd ans=0.;
	ll n=100;
	rep(x,1,n-1){
		if (A==0){
			if (x!=1)break;
		}
		rep(y,1,n-1){
			if (B==0){
				if (y!=1)break;
			}

			ll xx=abs(x-1);
			ll yy=abs(y-1);
			if (xx%g!=0)continue;
			if (yy%g!=0)continue;

			ll xxx=xx/g;
			ll yyy=yy/g;
			if (isn==true and (xxx+yyy)%2==1){
				continue;
			}

			ans+=1/POW((dd)(x+y),x+y);
		}
	}
	cout << ans << '\n';

}

int main(){
#if 1
	solve();

#else
	ll t;  cin >> t;
	rep(i, 0, t-1){
		solve();
	}
#endif
	return 0;
}