#include <bits/stdc++.h>
using namespace std;
ifstream in ("podm.in");
ofstream out ("podm.out");
int n, x, l[505], c[505], i, j, k;
long long d[505][505];
int main()
{
    ios_base::sync_with_stdio (false);
    cin.tie (0);
    cout.tie (0);
    in >> n;
    in >> x;
    for (i = 1; i <= n; ++i)
        l[i] = x, in >> x, c[i] = x;
    for (i = n; i >= 1; --i)
        for (j = i + 1; j <= n; ++j)
        {
            d[i][j] = LLONG_MAX;
            for (k = i; k < j; ++k)
                d[i][j] = min (d[i][j], d[i][k] + d[k + 1][j] + 1LL*l[i] * c[j] * c[k]);
        }
    out << d[1][n];
}