#include <bits/stdc++.h>
#ifdef __LOCAL__
#include <debug_local.h>
#endif
using namespace std;
const int mxN = 1e6 + 5;
long long a[mxN];
multiset<long long> s;
void testCase() {
int n;
cin >> n;
for (int i = 1; i <= n; i++) cin >> a[i];
for (int i = 1; i <= n; i++) a[i + n] = a[i];
for (int i = 1; i <= 2 * n; i++) a[i] += a[i - 1];
int x = (n + 1) / 2;
for (int i = x; i < x + x; i++) s.insert(a[i] - a[i - x]);
long long ans = *s.begin();
for (int i = x + 1; i <= 2 * n - x + 1; i++) {
s.erase(s.find(a[i - 1] - a[i - x - 1]));
s.insert(a[i + x - 1] - a[i - 1]);
ans = max(ans, *s.begin());
}
cout << ans << "\n";
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
testCase();
return 0;
}
