///~~~LOTA~~~///
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define append push_back
#define add insert
#define nl "\n"
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define all(x) (x).begin(),(x).end()
#define L0TA ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define N 500001
int n;
int a[N];
int get(int l,int r){
if(l>r)
return a[n]-a[l-1]+a[r];
return a[r]-a[l-1];
}
void solve(){
int m,o,p,q;
cin>>n;
m=(n-1)/2;
for(int i=o=1;i<=n;i++){
cin>>a[i];
a[i]+=a[i-1];
}
for(int i=1;i<=n;i++){
if(i>m) p=i-m;
else p=n-m+i;
if(m+i<=n) q=i+m;
else q=i+m-n;
o=max(o,min(get(p,i),get(i,q)));
}
cout<<o;
}
int main(){
L0TA;
solve();
return 0;
}
