func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long INF = 100000000;   const long long MAXN = 20100;   int n, a[MAXN], ans;   int main() {     ans = -INF;     cin >> n;     for (int i = 1; i <= n; i++) {       cin >> a[i];     }     for (int k = 1; k <= n; k++) {       if (n % k == 0) {         for (int j = 1; j <= k; j++) {           long long sum = 0, cnt = 0;           for (int i = j; i <= n; i += k) {             cnt++;             sum += a[i];           }           if (sum > ans && cnt >= 3) {             ans = sum;           }         }       }     }     cout << ans;     return 0;   }   