#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ar array
void solve() {
int n;
cin >> n;
vector<int> a(n * 2 + 1, 0);
for (int i = 1; i <= n;i++) cin >> a[i], a[i * 2] = a[i];
for (int i = 1; i <= n * 2;i++) {
a[i] += a[i - 1];
}
multiset<int>ms;
vector<int> res(2 * n + 1,0);
int m = (n + 1) / 2;
for (int i = 1; i <= 2 * n;i++) {
if (i + m - 1 <= 2 * n) ms.insert(a[i + m - 1] - a[i - 1]);
if (i > m) ms.erase(ms.find(a[i - 1] - a[i - m - 1]));
res[i] = *ms.begin();
}
cout << *max_element(res.begin(),res.end());
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int t = 1;
//cin >> t;
while (t--) {
solve();
cout << "\n";
}
return 0;
}
