#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3")

#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={1,0,-1,0,1,1,-1,-1,0};
const ll dx[9]={0,1,0,-1,1,-1,1,-1,0};
template <typename T> inline bool chmax(T &a, T b) {
  return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
  return ((a > b) ? (a = b, true) : (false));
}
int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  ll n;cin >> n;
  vl v(n);rep(i,n)cin >> v[i];
  vl rv=v;rev(all(rv));
  vpl pls(n);rep(i,n)pls[i]={v[i],i};sort(all(pls));
  vpl rpls(n);rep(i,n)rpls[i]={rv[i],i};sort(all(rpls));
  ll ans=0;
  for(ll k=1;k<=n;k++){
    const ll c=n/k;
    vl left(c+1);
    vl deg(c);
    rep(j,n){
      if(pls[j].second>=c*k)continue;
      ll f=pls[j].second/k;
      deg[f]++;
      if(deg[f]==(k+1)>>1)left[f+1]=pls[j].first*k;
    }
    rep(i,c)left[i+1]+=left[i];
    rep(i,c)chmax(left[i+1],left[i]);
    vl right(c+1);
    vl rdeg(c);
    rep(j,n){
      if(rpls[j].second>=c*k)continue;
      ll f=rpls[j].second/k;
      rdeg[f]++;
      if(rdeg[f]==(k+1)>>1)right[f+1]=rpls[j].first*k;
    }
    rep(i,c)right[i+1]+=right[i];
    rep(i,c)chmax(right[i+1],right[i]);
    rep(i,n/k+1)chmax(ans,left[i]+right[n/k-i]);
  }
  cout << ans << endl;
}