#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) __typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii; typedef long long ll;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }

vector<pair<int,double> > doDP(const int a[6], int n) {
	int maxX = 1;
	rep(i, n) maxX *= a[5];
	vector<double> dp(maxX+1);
	dp[1] = 1;
	rep(i, n) {
		for(int j = maxX; j >= 0; -- j) {
			double p = dp[j];
			dp[j] = 0;
			if(p < 1e-99) continue;
			p /= 6;
			rep(k, 6)
				dp[j * a[k]] += p;
		}
	}
	vector<pair<int,double> > v;
	rer(i, 0, maxX) if(dp[i] > 1e-99)
		v.push_back(mp(i, dp[i]));
	return v;
}

int main() {
	const int primes[6] = { 2, 3, 5, 7, 11, 13 };
	const int composites[6] = { 4, 6, 8, 9, 10, 12 };
	int P, C;
	while(~scanf("%d%d", &P, &C)) {
		auto dpP = doDP(primes, P);
		auto dpC = doDP(composites, C);
		double ans = 0;
		each(i, dpP) each(j, dpC)
			ans += i->first * i->second * j->first * j->second;
		printf("%.10f\n", ans);
	}
	return 0;
}