#include <bits/stdc++.h>

using namespace std;

ifstream f("podm.in");
ofstream g("podm.out");

unsigned long long n,i,j,k,d[510],dp[510][510];

int main()
{
    f>>n;
    for(i=1;i<=n+1;i++)f>>d[i];

    n++;
    for(i=n;i>=1;i--)
    {
        for(j=i+2;j<=n;j++)
        {
            dp[i][j]=100000000000000000LL;
            for(k=i+1;k<=j-1;k++)
            {
                dp[i][j]=min(dp[i][j],dp[i][k]+dp[k][j]+d[i]*d[j]*d[k]);
            }
        }
    }

    g<<dp[1][n];
    return 0;
}