#include<cstdio>
#include<algorithm>
using namespace std;
int main()
{
    freopen("podm.in","r",stdin);
    freopen("podm.out","w",stdout);
    int n,v[501];
    long long dp[501][501];
    scanf("%d",&n);
    for(int i=0;i<=n;++i) scanf("%d",&v[i]);
    for(int i=1;i<n;++i)
        for(int j=i+1;j<=n;++j)
        {
            long long m=1LL<<60;
            int x=v[j-i-1]*v[j];
            for(int k=j-i;k<j;++k)
                m=min(m,dp[j-i][k]+dp[k+1][j]+1LL*x*v[k]);
            dp[j-i][j]=m;
        }
    printf("%d",dp[1][n]);
    return 0;
}