#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
#define SZ(x) ((int)((x).size()))

template <typename T1, typename T2>
string print_iterable(T1 begin_iter, T2 end_iter, int counter) {
    bool done_something = false;
    stringstream res;
    res << "[";
    for (; begin_iter != end_iter and counter; ++begin_iter) {
        done_something = true;
        counter--;
        res << *begin_iter << ", ";
    }
    string str = res.str();
    if (done_something) {
        str.pop_back();
        str.pop_back();
    }
    str += "]";
    return str;
}

vector<int> SortIndex(int size, std::function<bool(int, int)> compare) {
    vector<int> ord(size);
    for (int i = 0; i < size; i++) ord[i] = i;
    sort(ord.begin(), ord.end(), compare);
    return ord;
}

template <typename T>
bool MinPlace(T& a, const T& b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template <typename T>
bool MaxPlace(T& a, const T& b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template <typename S, typename T>
ostream& operator <<(ostream& out, const pair<S, T>& p) {
    out << "{" << p.first << ", " << p.second << "}";
    return out;
}

template <typename T>
ostream& operator <<(ostream& out, const vector<T>& v) {
    out << "[";
    for (int i = 0; i < (int)v.size(); i++) {
        out << v[i];
        if (i != (int)v.size()-1) out << ", ";
    }
    out << "]";
    return out;
}

template<class TH>
void _dbg(const char* name, TH val){
    clog << name << ": " << val << endl;
}
template<class TH, class... TA>
void _dbg(const char* names, TH curr_val, TA... vals) {
    while(*names != ',') clog << *names++;
    clog << ": " << curr_val << ", ";
    _dbg(names+1, vals...);
}

#if DEBUG && !ONLINE_JUDGE
    ifstream input_from_file("input.txt");
    #define cin input_from_file

    #define dbg(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
    #define dbg_arr(x, len) clog << #x << ": " << print_iterable(x, x+len, -1) << endl;
#else
    #define dbg(...)
    #define dbg_arr(x, len)
#endif

///////////////////////////////////////////////////////////////////////////
//////////////////// DO NOT TOUCH BEFORE THIS LINE ////////////////////////
///////////////////////////////////////////////////////////////////////////

struct State {
    int l, r;
    int a, b;
};

bool operator <(const State& A, const State& B) {
    return (A.l != B.l)?(A.l < B.l):(
        (A.r != B.r)?(A.r < B.r):
        ((A.a != B.a)?(A.a < B.a):(A.b < B.b)));
}

const int MAXN = 20;
LL vec[MAXN];
map<State, LL> memo;
LL solve(State S) {
    if (S.l + 1 == S.r) return 0;
    if (S.l + 2 == S.r) return (S.a + S.b)*vec[S.l+1];
    if (memo.count(S)) return memo[S];
    LL res = 1e18;
    for (int i = S.l+1; i < S.r; i++) {
        LL ris = vec[i] * (S.a + S.b);

        State T = S;
        T.r = i;
        T.b = S.a + S.b;
        ris += solve(T);

        T = S;
        T.l = i;
        T.a = S.a + S.b;
        ris += solve(T);

        res = min(res, ris);
    }
    memo[S] = res;
    return res;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); // Remove in problems with online queries!

    int N;
    cin >> N;
    for (int i = 0; i < N; i++) cin >> vec[i];
    State S;
    S.l = 0, S.r = N-1, S.a = 1, S.b = 1;
    LL res = vec[0] + vec[N-1] + solve(S);
    cout << res << "\n";
}


Measured memory_bytes: 8320