#include <bits/stdc++.h>
#define int long long
#define ff first
#define ss second
using namespace std;
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
int n;
cin >> n;
int a[n];
for (int i = 0;i < n;i++) {
cin >> a[i];
}
int ans = 0;
int diff = (n + 1) / 2;
int sum = 0;
vector <int> v;
for (int i = n - diff;i < n;i++) {
sum += a[i];
}
for (int i = 0;i < n;i++) {
sum -= a[(i - diff + n) % n];
sum += a[i];
v.push_back(sum);
// cout << sum << ' ';
}
multiset <int> ms;
for (int i = 0;i < diff;i++) {
ms.insert(v[i]);
}
ans = *ms.begin();
for (int i = diff;i < n + diff;i++) {
ms.erase(ms.find(v[i - diff]));
ms.insert(v[i % n]);
ans = max(ans, *ms.begin());
}
cout << ans << endl;
}
