#include <bits/stdc++.h>
#define EPS 1e-9
#define INF 1070000000LL
#define MOD 1000000007LL
#define fir first
#define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++)
#define numa(x,a) for(auto x: a)
#define ite iterator
#define mp make_pair
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define pb push_back
#define pf push_front
#define sec second
#define sz(x) ((int)(x).size())
#define ALL( c ) (c).begin(), (c).end()
#define gcd(a,b) __gcd(a,b)
#define mem(x,n) memset(x,n,sizeof(x))
#define endl "\n"
using namespace std;
template <int POS, class TUPLE> void deploy(std::ostream &os, const TUPLE &tuple){}
template <int POS, class TUPLE, class H, class ...Ts> void deploy(std::ostream &os, const TUPLE &t){ os << (POS == 0 ? "" : ", ") << get<POS>(t); deploy<POS + 1, TUPLE, Ts...>(os, t); }
template <class T,class U> std::ostream& operator<<(std::ostream &os, std::pair<T,U> &p){ os << "(" << p.first <<", " << p.second <<")";return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::vector<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::set<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T, class K> std::ostream& operator<<(std::ostream &os, std::map<T, K> &mp){ int remain = mp.size(); os << "{"; for(auto e: mp) os << "(" << e.first << " -> " << e.second << ")" << (--remain == 0 ? "}" : ", "); return os; }
#define DEBUG1(var0) { std::cerr << (#var0) << "=" << (var0) << endl; }
#define DEBUG2(var0, var1) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG1(var1); }
#define DEBUG3(var0, var1, var2) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG2(var1,var2); }
#define DEBUG4(var0, var1, var2, var3) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG3(var1,var2,var3); }
using ll = long long;

vector <int> nums = {2,3,5,7,11,13};
vector <int> nums2 = {4,6,8,9,10,12};

int main()
{
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  int P,C;
  bool f1,f2;
  cin >> P >> C;
  map <int,int> memo[2];
  memo[0][1] = 1;
  f1 = false;
  rep(k,P){
    bool pre = k % 2 != 0;
    bool cur = !pre;
    memo[cur].clear();
    numa(x,memo[pre]){
      numa(y,nums){
        memo[cur][x.fir * y] += x.sec;
      }
    }
    f1 = cur;
  }
  
  map <int,int> memo2[2];
  memo2[0][1] = 1;
  f2 = false;
  rep(k,C){
    bool pre = k % 2 != 0;
    bool cur = !pre;
    memo2[cur].clear();
    numa(x,memo2[pre]){
      numa(y,nums2){
        memo2[cur][x.fir * y] += x.sec;
      }
    }
    f2 = cur;
  }
  //DEBUG1(memo[f1]);
  //DEBUG1(memo2[f2]);
  long double ans = 0;
  numa(x,memo[f1]){
    numa(y,memo2[f2]){
      ans += (ll) x.fir * y.fir * x.sec * y.sec;
    }
  }
  cout << fixed << setprecision(13) << ans / pow(6,P+C) << endl;
  return 0;
}