#include <bits/stdc++.h>
using namespace std;
long long dp[1010],a[1010];
long long mul[1010][1010];
int main(){
freopen("split.in","r",stdin);
freopen("split.out","w",stdout);
int n;
cin>>n;
for(int i=1;i<=n;i++)
{
cin>>a[i];
}
for(int i=1;i<=n;i++)
{
mul[i][i]=a[i];
for(int j=i+1;j<=n;j++)
{
mul[i][j]=mul[i][j-1]*a[j]%1000;
}
}
dp[1]=a[1];
for(int i=2;i<=n;i++)
{
for(int j=1;j<=i;j++)
{
dp[i]=max(dp[i],dp[j-1]+mul[j][i]);
}
}
cout<<dp[n]<<endl;
return 0;
}