#include <fstream>
#include <algorithm>
#include <climits>
using namespace std;
ifstream cin("podm.in");
ofstream cout("podm.out");
int n;
long long v[505],dp[505][505];

struct mat
{
    long long lat;
    long long col;
}d[505];

int main()
{
    cin>>n;
    for(int i =1;i<=n+1;i++)
        cin>>v[i];
    for(int i=1;i<=n;i++)
    {
        d[i].lat=v[i];
        d[i].col=v[i+1];
    }
    for(int i=1;i<=n;i++)
    {
        dp[i][i+1]=d[i].lat * d[i].col * d[i+1].col;
    }
    for(int l=3;l<=n;l++)
        for(int i=1;i+l-1<=n;i++)
        {
            int dr= i+l-1;
            dp[i][dr]=LLONG_MAX;
            for(int k = i;k<dr;k++)
            {
                dp[i][dr]=min(dp[i][dr],dp[i][k] + dp[k+1][dr] + 1ll*d[i].lat*d[k+1].lat*d[dr].col);
            }
        }
    cout<<dp[1][n];
    return 0;
}