#include <bits/stdc++.h>
#define NM 505
using namespace std;
ifstream fin ("podm.in");
ofstream fout ("podm.out");

struct Nr
{
    int x, y;
};

int n;
Nr v[NM];
int dp[NM][NM];
int mx = 1;

int main()
{
    fin >> n;
    fin >> v[1].x;
    mx = v[1].x;
    for(int i = 1 ; i <= n ; i++)
    {
        fin >> v[i].y;
        mx *= v[i].y;
        v[i+1].x = v[i].y;
    }
    for(int i = 1 ; i < n ; i++)
    {
        dp[i][i+1] = v[i].x * v[i].y * v[i+1].y;
    }
    for(int d = 3 ; d <= n ; d++)
    {
        for(int i = 1, j = d ; j <= n ; i++, j++)
        {
            dp[i][j] = mx;
            for(int k = i ; k < j ; k++)
            {
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + v[i].x * v[k].y * v[j].y);
            }
        }
    }
    fout << dp[1][n];
    return 0;
}