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

typedef long double db;
typedef long long ll;
db ksm(db a,int x){
    db ret=1.0;
    for (;x;x>>=1,a=a*a) if (x&1) ret=ret*a;
    return ret;
}

const int maxn=20;
ll C[maxn+50][maxn+50];

int n;
db p[10];

int main(){
    ios_base::sync_with_stdio(false);

    C[0][0]=1;
    for (int i=1;i<=maxn;i++){
        C[i][0]=1;
        for (int j=1;j<=i;j++) C[i][j]=C[i-1][j-1]+C[i-1][j];
    }

    cin >> n;
    for (int i=1;i<=4;i++) cin >> p[i];
    priority_queue<pair<db,ll>,vector<pair<db,ll>>,greater<pair<db,ll>>> pq;
    for (int a=0;a<=n;a++){
        for (int b=0;b<=n-a;b++){
            for (int c=0;c<=n-a-b;c++){
                int d=n-a-b-c;
                db prod=ksm(p[1],a)*ksm(p[2],b)*ksm(p[3],c)*ksm(p[4],d);
                ll fac=C[a+b+c+d][a]*C[b+c+d][b]*C[c+d][c];
                pq.push(make_pair(prod,fac));
            }
        }
    }
    db ans=0;
    while (1){
        auto [p1,f1]=pq.top();
        pq.pop();
        if (pq.size()==0 && f1==1){
            break;
        }
        if (f1>1){
            ans+=p1*2*(f1/2);
            pq.push(make_pair(p1*2,f1/2));
            if (f1%2==1) pq.push(make_pair(p1,1LL));
        }
        else{
            auto [p2,f2]=pq.top();
            pq.pop();

            ans+=p1+p2;
            pq.push(make_pair(p1+p2,1LL));
            if (f2>1) pq.push(make_pair(p2,f2-1));
        }
    }
    cout << fixed << setprecision(12) << ans << "\n";
    return 0;
}