#include <iostream>
#include <cstring>
using namespace std;

const int MAXN = 1005;
int price[MAXN];
int dp[MAXN];

int main()
{
    int n;
    cin >> n;
    for(int i = 1; i <= n; ++i)
    {
        cin >> price[i];
    }

    memset(dp, 0, sizeof(dp));

    for(int i = 1; i <= n; ++i)
    {
        for(int j = 1; j <= i; ++j)
        {
            if(dp[i - j] + price[j] > dp[i])
            {
                dp[i] = dp[i - j] + price[j];
            }
        }
    }
    cout << dp[n] << endl;
    return 0;
}