#include<bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
typedef long long LL;
typedef unsigned long long uLL;
typedef pair<int,int> pii;

const int inf=0x3f3f3f3f;
const LL Linf=1ll<<61;

int n,a[20];

map<pii,LL> dp[20][20];
LL dfs(int l,int r,int tl,int tr)
{
	if(l==r-1)return 0;
	if(dp[l][r].find(mp(tl,tr))!=dp[l][r].end())return dp[l][r][mp(tl,tr)];
	LL ret=Linf;
	for(int m=l+1;m<r;m++)ret=min(ret,dfs(l,m,tl,tl+tr)+dfs(m,r,tl+tr,tr)+(LL)(tl+tr)*a[m]);
	return (dp[l][r][mp(tl,tr)]=ret);
}

int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++)scanf("%d",a+i);
	printf("%lld\n",dfs(1,n,1,1)+a[1]+a[n]);
	return 0;
}