#include <bits/stdc++.h>

using namespace std;

const int N = 50 + 10;

//__int128专用
typedef __int128 LL;
const LL INF = 1e38;
LL read() { // 快读
    LL x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}
void write(LL x) { // 快写
    if (x < 0) putchar('-'), x = -x;
    if (x > 9) write(x / 10);
    putchar(x % 10 + '0');
}

LL w[N];
LL f[N][N];

// 计算[l,r]之间的三角剖分最大值
LL dfs(int l, int r) {
    LL &v = f[l][r];
    if (v != INF) return v;         // 记忆化
    if (r - l < 2) return v = 0;    // 不够三个点，哪来的剖分值
    for (int k = l + 1; k < r; k++) // 中间点k不能与l,r重合
        v = min(v, dfs(l, k) + dfs(k, r) + w[l] * w[r] * w[k]);
    return v;
}

int main() {
    int n;
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) w[i] = read();

    // 初始化极值
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            f[i][j] = INF;

    write(dfs(1, n));
    return 0;
}