#include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for (int i=0; i<(n); ++i)
#define RREP(i, n) for (int i=(int)(n)-1; i>=0; --i)
#define FOR(i, a, n) for (int i=(a); i<(n); ++i)
#define RFOR(i, a, n) for (int i=(int)(n)-1; i>=(a); --i)

#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()

#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl
#define DEBUG(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<<endl;

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "[";
  REP(i, SZ(v)) {
    if (i) os << ", ";
    os << v[i];
  }
  return os << "]";
}

template<class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  return os << "(" << p.first << " " << p.second << ")";
}

template<class T>
bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

template<class T>
bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return true;
  }
  return false;
}

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;
using vvi = vector<vi>;
using vvll = vector<vll>;

const ll MOD = 1e9 + 7;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;
const ld eps = 1e-9;

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);

  ll a, b; cin >> a >> b;
  a = abs(a);
  b = abs(b);
  ll g = gcd(a, b);

  if(a == 0 && b == 0) {
    cout << 0.25 << endl;
    return 0;
  } else if(a == 0 || b == 0) {
    if(a == 0) swap(a, b);
    ld ans = 0.0;
    for(ll i = 1;i<=15;i+=a) {
      for(ll j = 1;j<=15;j+=a) {
        if(i + j > 15) break;
        ans += 1.0 / pow(i + j, i + j);
      }
    }
    cout << ans << endl;
    return 0;
  } else if((a / g + b / g) % 2 == 0) {
    ld ans = 0.0;
    for(ll i = 1;i<=15;i+=g) {
      for(ll j = 1;j<=15;j+=g) {
        if(i + j > 15) break;
        if(((i-1) / g + (j-1) / g) % 2 == 0) {
          ans += 1.0 / pow(i+j, i+j);
        }
      }
    }
    cout << ans << endl;
    return 0;
  }


  ld ans = 0.0;
  for(ll i = 1;i<=15;i+=g) {
    for(ll j = 1;j<=15;j+=g) {
      if(i + j > 15) break;
      ans += 1.0 / pow(i + j, i + j);
    }
  }
  cout << ans << endl;

  return 0;
}