#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<ll> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    ll ans = 0;
    for (int k = 1; k <= n; k++) {
        int max_num = n / k;
        vector<ll> memoL(max_num + 1, 0);
        ll tmp = 0;
        for (int i = 0; i < max_num; i++) {
            vector<ll> v(k);
            for (int j = 0; j < k; j++) {
                v[j] = a[i * k + j];
            }
            sort(v.begin(), v.end());
            tmp += v[(k - 1) / 2] * k;
            memoL[i + 1] = max(memoL[i], tmp);
        }

        vector<ll> memoR(max_num + 1, 0);
        tmp = 0;
        for (int i = 0; i < max_num; i++) {
            vector<ll> v(k);
            for (int j = 0; j < k; j++) {
                v[j] = a[n - 1 - i * k - j];
            }
            sort(v.begin(), v.end());
            tmp += v[(k - 1) / 2] * k;
            memoR[i + 1] = max(memoR[i], tmp);
        }

        for (int i = 0; i <= max_num; i++) {
            ans = max(ans, memoL[i] + memoR[max_num - i]);
        }
    }
    cout << ans << "\n";
    return 0;
}