#include <cstdio>
#include <cstring>
#include <cctype>
#include <algorithm>
using namespace std;
typedef long long i64;
inline int read(int f = 1, int x = 0, char ch = ' ')
{
    while(!isdigit(ch = getchar())) if(ch == '-') f = -1;
    while(isdigit(ch)) x = x*10+ch-'0', ch = getchar();
    return f*x;
}
const int N = 18+5;
int n; i64 a[N];
i64 dfs(int l, int r, int x, int y)
{
    if(l+1 == r) return 0; i64 ret = 1e18;
    for(int i = l+1; i < r; ++i) ret = min(ret, dfs(l, i, x, x+y)+dfs(i, r, x+y, y)+a[i]*(x+y));
    return ret;
}
int main()
{
    n = read(); for(int i = 1; i <= n; ++i) a[i] = read();
    printf("%lld\n", dfs(1, n, 1, 1)+a[1]+a[n]);
    return 0;
}