#include<bits/stdc++.h>
#define MAXN 19
#define INF 9223372036854775807
using namespace std;

inline long long read()
{
	long long x=0,f=1;char ch=getchar();
	while(!isdigit(ch)){if(ch=='-') f=-f;ch=getchar();}
	while(isdigit(ch)){x=x*10+ch-'0';ch=getchar();}
	return x*f;
}

long long n,m;
long long a[MAXN];
long long dfs(long long l,long long r,long long x,long long y)
{
	if(l==r-1) return a[l]*x+a[r]*y;
	long long ans=INF;
	for(register long long m=l+1;m<r;++m) ans=min(ans,dfs(l,m,x,x+y)+dfs(m,r,x+y,y)-a[m]*(x+y));
	return ans;
}

int main()
{
	n=read();
	for(register long long i=1;i<=n;++i) a[i]=read();
	printf("%lld",dfs(1,n,1,1));
	return 0;
}