#include <bits/stdc++.h>
using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef pair<LL, LL> PLL;
typedef vector<LL> VL;

#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define FF first
#define SS second
template<class S, class T>
istream& operator>>(istream& is, pair<S,T>& p){
  return is >> p.FF >> p.SS;
}

const double EPS = 1e-10;
const double PI  = acos(-1.0);
const LL MOD = 1e9+7;

void dfs(VL& xs, map<LL,int>& res, int n, LL acc = 1){
  if(n == 0){
	res[acc]++;
	return;
  }
  for(auto x: xs)
	dfs(xs, res, n-1, acc*x);
}

int main(){
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  VL ps{2,3,5,7,11,13};
  VL qs{4,6,8,9,10,12};
  int P, C; cin >> P >> C;
  map<LL,int> memo1, memo2;
  dfs(ps, memo1, P);
  dfs(qs, memo2, C);

  double ans = 0., num = pow(6,P+C);
  for(auto& p1: memo1) for(auto& p2: memo2){
	  ans += p1.FF*p2.FF*p1.SS*p2.SS/num;
	}
  cout << fixed << setprecision(10) << ans << endl;

  return 0;
}