using namespace std;
//#include <iostream>
#include <fstream>
ifstream cin ("podm.in");ofstream cout ("podm.out");
pair < long long , long long > v[510];
int aux[510];
long long dp[510][510];
const long long inf = 1e18;
int main() {
    //freopen("input", "r", stdin);freopen("output", "w", stdout);
    int n;
    cin>>n;
    for (int i=1; i<=n+1; i++){
        cin>>aux[i];
    }
    for (int i=1; i<=n; i++){
        v[i] = {aux[i] , aux[i+1]};
    }
    for (int l=2; l<=n; l++){
        for (int i=1; i<=n-l+1; i++){
            dp[i][l] = inf;
            int j = i+l-1;
            for (int l1=1; l1<l; l1++){
                int l2 = l-l1;
                int k = i + l1;
                dp[i][l] = min(dp[i][l] , dp[i][l1] + dp[k][l2] + v[i].first * v[k].first * v[j].second);
            }
        }
    }
    cout<<dp[1][n];
    return 0;
}