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#include<bits/stdc++.h>
#include<algorithm>
 
#define spd_emergency ios_base::sync_with_stdio(false);cin.tie(NULL);
#define ll long long
#define ull unsigned long long
#define mp make_pair
#define ff first
#define ss second
#define mloop(i) for(auto i=m.begin();i!=m.end();i++)
#define pb push_back
#define pll pair<ll,ll> 
#define pii pair<int,int> 
#define mod1 1125899906842597LL
 
using namespace std;
vector<bool> prime(200002,true);
void seive(ll mx)
{
   prime[0]=prime[1]=false;
   for(ll i=2;i*i<=mx;i++)
   {
      if(prime[i])
      {
         for(ll j=i*i;j<=mx;j+=i)
         {
            prime[j]=false;
         }
      }
   }
}
 
const ll M = 1e9+7;
const ll Mxn = 3e5;
 
ll power(ll i,ll p)
{
   ll ans=1;
   while(p)
   {
      if(p & 1)
         ans = (ans*i)%M;
      i = (i*i)%M;
      p/=2;
   }
   return ans%M;
}
 
vector<ll> z_function(vector<ll> s) {
    ll n = (ll) s.size();
    vector<ll> z(n);
    for (ll i = 1, l = 0, r = 0; i < n; ++i) {
        if (i <= r)
            z[i] = min (r - i + 1, z[i - l]);
        while (i + z[i] < n && s[z[i]] == s[i + z[i]])
            ++z[i];
        if (i + z[i] - 1 > r)
            l = i, r = i + z[i] - 1;
    }
    return z;
}
 
int main()
{
   ll t=1, sum=0;
   while(t--)
   {
      ll n,ans=LLONG_MIN;
      cin>>n;
      assert(n>=1 && n<=200000);
      //sum+=n;
      vector<ll> a(n), pref(n+1,0);
      for(ll i=0;i<n;i++)
      {
         cin>>a[i];
         assert(a[i]>=-1000000000 && a[i]<=1000000000);
         pref[i+1] = pref[i]+a[i];
      }
      vector<ll> z = z_function(a);
      for(ll i=0;i<n;i++)
      {
         if(z[i]+i == n)
         {
            ans = max(ans, pref[z[i]]);
         }
      }
      cout<<max(ans, pref[n])<<endl;
   }
   return 0;
}