#include <iostream>
#include <cstring>
using namespace std;
const int N = 105;
int n, a[N], dp[N][N];
int main() {
	scanf("%d", &n);
	memset(dp, 0x3f, sizeof dp);
	for (int i = 1; i <= n; i++) {
		scanf("%d", &a[i]);
		dp[i][i] = a[i - 1] * a[i] * a[i + 1];
	}
	for (int len = 2; len <= n - 2; len++) {
		for (int l = 1; l + len - 1 < n; l++) {
			int r = l + len - 1;
			for (int k = l + 1; k <= r - 1; k++) {
				dp[l][r] = min(dp[l][r], dp[l][k - 1] + dp[k + 1][r] + a[l - 1] * a[k] * a[r + 1]);
			}
			dp[l][r] = min(dp[l][r], dp[l][r - 1] + a[l - 1] * a[r] * a[r + 1]);
			dp[l][r] = min(dp[l][r], dp[l + 1][r] + a[l - 1] * a[l] * a[r + 1]);
		}
	}
	printf("%d", dp[2][n - 1]);
    return 0;
}