#include "bits/stdc++.h"
using namespace std;
     
#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl
     
typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
const int inf = 1000000001;
const ll INF = 1e16;
#define MOD 1000000007
#define mod 1000000009
#define pi 3.14159265358979323846
#define Sp(p) cout<<setprecision(15)<<fixed<<p<<endl;
int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };

ll ans = 0;
int p, c;
vi so = {2, 3, 5, 7, 11, 13};
vi go = {4, 6, 8, 9, 10, 12};

void dfs(int cnt, ll sum) {
  if (cnt == p + c) {
    ans += sum;
    return;
  }
  if (cnt < p) {
    for (int i = 0; i < 6; i++) {
      dfs(cnt + 1, sum * so[i]);
    }
  }
  else {
    for (int i = 0; i < 6; i++) {
      dfs(cnt + 1, sum * go[i]);
    }
  }
}
  

int main() {
  cin >> p >> c;
  dfs(0, 1);
  Sp(ans / pow(6, p + c));
}