#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
/*#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")*/

using namespace __gnu_pbds;
using namespace std;

#define ll long long
#define ld long double
#define mp make_pair
#define what_is(x) cerr << #x << " is " << x << endl;

typedef tree<
        int,
        null_type,
        less<int>,
        rb_tree_tag,
        tree_order_statistics_node_update>
        ordered_set;

void print(auto &a)
{
    for (auto s: a) cout<<s<<' ';
    cout<<endl;
}

void get(vector<auto> &a)
{
    for (int i = 0; i<(int)a.size(); i++) cin>>a[i];
}

const int p = 998244353;


int mul(int a, int b) {
    return (1LL * a%p * b%p) % p;
}

int add(int a, int b) {
    int s = (a+b);
    s = s%p;
    if (s<0) s+=p;
    return s;
}

int sub(int a, int b) {
    int s = (a-b);
    s = s%p;
    if (s<0) s+=p;
    return s;
}

int po(int a, int deg)
{
    if (deg==0) return 1;
    if (deg%2==1) return mul(a, po(a, deg-1));
    int t = po(a, deg/2);
    return mul(t, t);
}

int inv(int n)
{
    return po(n, p-2);
}

vector<int> Z(vector<int> s)
{
    int n = s.size();
    vector<int> z(n);
    int L = 0, R = 0;
    for (int i = 1; i < n; i++) {
        if (i > R) {
            L = R = i;
            while (R < n && s[R-L] == s[R]) R++;
            z[i] = R-L; R--;
        } else {
            int k = i-L;
            if (z[k] < R-i+1) z[i] = z[k];
            else {
                L = i;
                while (R < n && s[R-L] == s[R]) R++;
                z[i] = R-L; R--;
            }
        }
    }
    return z;
}

mt19937 rnd(time(0));

struct Line {
    mutable ll k, m, p;
    bool operator<(const Line& o) const { return k < o.k; }
    bool operator<(ll x) const { return p < x; }
};

struct CHT : multiset<Line, less<>> {
    // (for doubles, use inf = 1/.0, div(a,b) = a/b)
    const ll inf = LLONG_MAX;
    ll div(ll a, ll b) { // floored division
        return a / b - ((a ^ b) < 0 && a % b); }
    bool isect(iterator x, iterator y) {
        if (y == end()) { x->p = inf; return false; }
        if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
        else x->p = div(y->m - x->m, x->k - y->k);
        return x->p >= y->p;
    }
    void add(ll k, ll m) {
        auto z = insert({k, m, 0}), y = z++, x = y;
        while (isect(y, z)) z = erase(z);
        if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
        while ((y = x) != begin() && (--x)->p >= y->p)
            isect(x, erase(y));
    }
    ll query(ll x) {
        assert(!empty());
        auto l = *lower_bound(x);
        return l.k * x + l.m;
    }
};

const ll INF = 1e18;

int n;
vector<ll> a;

set<pair<int, int>> pairs;

vector<vector<map<pair<int, int>, ll>>> dp;

void dfs(pair<int, int> cur, int height)
{
    pairs.insert(cur);
    if (height==0) return;
    pair<int, int> p1 = mp(cur.first, cur.first+cur.second);
    pair<int, int> p2 = mp(cur.first+cur.second, cur.second);
    dfs(p1, height-1);
    dfs(p2, height-1);
}

void dfs_true(int i, int j, pair<int, int> coef)
{
    if (dp[i][j].find(coef)!=dp[i][j].end()) return;
    if (j==i+1) {dp[i][j][coef] = coef.first*a[i] + coef.second*a[j]; return;}
    ll minn = INF;
    for (int k = i+1; k<j; k++)
    {
        pair<int, int> p1 = mp(coef.first, coef.first+coef.second);
        pair<int, int> p2 = mp(coef.first+coef.second, coef.second);
        dfs_true(i, k, p1);
        dfs_true(k, j, p2);
        minn = min(minn, dp[i][k][p1] + dp[k][j][p2] - (coef.first + coef.second)*a[k]);
        dp[i][j][coef] = minn;
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    //freopen("input.txt", "r", stdin);
    cin>>n;
    a.resize(n);
    for (int i = 0; i<n; i++) cin>>a[i];
    dp = vector<vector<map<pair<int, int>, ll>>>(n, vector<map<pair<int, int>, ll>>(n));
    pair<int, int> s = mp(1, 1);
    /*dfs(s, n-2);
    cout<<pairs.size();*/
    dfs_true(0, n-1, s);
    cout<<dp[0][n-1][s];
}



Measured memory_bytes: 33024