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

using ll = long long;
using ld = long double;

const ld pi = acos(-1);

ll C[21][21];

ll n;

vector<pair<ld, ll>> v;
ld p[4];

void dfs(ll i, ll t, ll ct, ld x) {
    if (i == 4) {
        if (t == n) {
            v.push_back({x, ct});
        }
        return;
    }

    for (ll j = 0; j + t <= n; j++) {
        dfs(i + 1, j + t, ct * C[n - t][j], x);
        x *= p[i];
    }
}

int main() {
    C[0][0] = 1;
    for (ll i = 1; i <= 20; i++) {
        for (ll j = 0; j <= i; j++) {
            C[i][j] = C[i - 1][j];
            if (j > 0) C[i][j] += C[i - 1][j - 1];
        }
    }

    cin >> n;
    for (ll i = 0; i < 4; i++) cin >> p[i];

    dfs(0, 0, 1, 1);

    sort(v.begin(), v.end());
    multiset<pair<ld, ll>> s(v.begin(), v.end());

    ll ct = 1LL << (2 * n);
    ll t = 0;
    // for (auto [x, y]: v) {
    //     cout << x << " " << y << endl;
    // }
    // cout << ct << " " << t << '\n';

    ld ans = 0;
    while (ct > 1) {
        auto [x, c] = *s.begin();
        s.erase(s.begin());
        // cout << x << " " << c << " " << ct << endl;
        if (c >= 2) {
            ans += 2 * x * (c / 2);
            ct -= c / 2;
            s.insert({2 * x, c / 2});
            c %= 2;
        }

        if (c == 1 && ct > 1) {
            assert(s.size());
            auto [y, d] = *s.begin();
            s.erase(s.begin());
            ans += x + y;
            ct--;
            s.insert({x + y, 1});
            --d;
            if (d > 0) s.insert({y, d});
        }
    }
    cout << setprecision(12) << fixed << ans << '\n';
}