#include <bits/stdc++.h>
inline long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
inline void sub(long long &a, long long b) {
  a -= b;
  if (a < 0) a += 1000000007;
}
inline void add(long long &a, long long b) {
  a += b;
  if (a >= 1000000007) a -= 1000000007;
}
template <typename T>
inline T const &MAX(T const &a, T const &b) {
  return a > b ? a : b;
}
template <typename T>
inline T const &MIN(T const &a, T const &b) {
  return a < b ? a : b;
}
inline long long qp(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % 1000000007;
    a = a * a % 1000000007, b >>= 1;
  }
  return ans;
}
inline long long qp(long long a, long long b, long long c) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % c;
    a = a * a % c, b >>= 1;
  }
  return ans;
}
using namespace std;
const unsigned long long ba = 233;
const double eps = 1e-5;
const long long INF = 0x3f3f3f3f3f3f3f3f;
const int N = 20000 + 10, maxn = 1000000 + 10, inf = 0x3f3f3f3f;
int a[N], n, ans;
void gao(int x) {
  for (int i = 1; i <= x; i++) {
    int sum = 0, k = 0;
    for (int j = i; j <= n; j += x, k++) sum += a[j];
    if (k >= 3) ans = max(ans, sum);
  }
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
  ans = -inf;
  for (int i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      gao(i);
      if (i * i != n) gao(n / i);
    }
  }
  printf("%d\n", ans);
  return 0;
}
