#include <iostream>
#include <vector>
#include <limits>
using namespace std;

const int MAXN = 2005; // 根据题目要求，1 ≤ n ≤ 2 * 10^6

int main() {
    int n;
    cin >> n;
    
    vector<int> w(n + 1);
    for (int i = 0; i <= n; ++i) {
        cin >> w[i];
    }
    
    // 优化为一维dp数组
    vector<int> dp(n + 1, 0);
    
    // 开始动态规划
    for (int len = 2; len <= n; ++len) {
        for (int i = 1; i <= n - len + 1; ++i) {
            int j = i + len - 1;
            dp[j] = numeric_limits<int>::max();
            for (int k = i; k < j; ++k) {
                int cost = dp[k] + dp[k + 1] + w[i - 1] * w[k] * w[j];
                if (cost < dp[j]) {
                    dp[j] = cost;
                }
            }
        }
    }
    
    // 输出结果
    cout << dp[n] << endl;
    
    return 0;
}