#include <fstream>

using namespace std;

ifstream cin("podm.in");
ofstream cout("podm.out");

const int MAX = 501;
long long dp[MAX][MAX], v[MAX];
int n;

int main()
{
    cin >> n;
    for(int i = 0; i <= n; ++i) {
        cin >> v[i];
    }

    for(int nr = 2; nr <= n; ++nr) {
        int i = 1, j = i + nr - 1;

        while(j <= n) {
            dp[i][j] = 1ll << 60;
            for(int k = i; k < j; ++k) {
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + v[i - 1]  v[k] * v[j]);
            }

            ++i;
            ++j;
        }
    }

    cout << dp[1][n];

    return 0;
}