#include<iostream>
#include<cstring>
using namespace std;
const int N=400;
int w[N];
int f[N][N];
int n;
int ans=0xcf;
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>w[i];
        w[i+n]=w[i];
    }
    memset(f,0xcf,sizeof f);
    for(int len=1;len<=n+1;len++)
    {
        for(int i=1;i+len-1<=2*n;i++)
        {
            int j=i+len-1;
            if(len<3) f[i][j]=0;
            else
            {
                for(int k=i+1;k<j;k++)
                    f[i][j]=max(f[i][j],f[i][k]+f[k][j]+w[i]*w[k]*w[j]);
            }
        }
    }
    for(int i=1;i+n<=2*n;i++)
        ans=max(ans,f[i][i+n]);
    cout<<ans;
    return 0;
}