#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>

int n, org[22];
map<pii,ll>mp[22][22];

ll gao(int l,int r,int a,int b){
    if (l+1==r) return 0;
    if (l+2==r) return org[l+1]*(ll)(a+b);
    if (mp[l][r].count({a,b})) return mp[l][r][{a,b}];
    ll res=1e100;
    for (int i=l+1;i<=r-1;++i){
        ll t=gao(l,i,a,a+b)+org[i]*(ll)(a+b)+gao(i,r,a+b,b);
        res=min(res,t);
    }
    return mp[l][r][{a,b}]=res;
}

int main(){
    cin>>n;
    for (int i=1;i<=n;++i)
        cin>>org[i];
    cout<<gao(1,n,1,1)+org[1]+org[n]<<endl;
}