#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
const long long oo = 1ll<<61;

int main()
{
	ios::sync_with_stdio(false);
	freopen("podm.in", "r", stdin);
	freopen("podm.out", "w", stdout);
	int n;
	cin >> n;
	vector<int> a(n+1);
	for (auto& x: a) {
		cin >> x;
	}
	vector<vector<long long>> dp(n, vector<long long>(n+1, oo));
	for (int i = 0; i < n; i++) {
		dp[i][i+1] = 0;
	}
	for (int len = 2; len <= n; len++) {
		for (int i = 0, j = len; j <= n; i++, j++) {
			for (int k = i+1; k < j; k++) {
				dp[i][j] = min(dp[i][j], dp[i][k]+dp[k][j]+(long long)a[i]*a[k]*a[j]);
			}
		}
	}
	printf("%lld\n", dp[0][n]);
	return 0;
}