#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#define DEBUG(...) debug(#__VA_ARGS__, __VA_ARGS__);
#else
#define DEBUG(...) 6;
#endif
template<typename T, typename S> ostream& operator << (ostream &os, const pair<T, S> &p) {return os << "(" << p.first << ", " << p.second << ")";}
template<typename C, typename T = decay<decltype(*begin(declval<C>()))>, typename enable_if<!is_same<C, string>::value>::type* = nullptr>
ostream& operator << (ostream &os, const C &c) {bool f = true; os << "["; for (const auto &x : c) {if (!f) os << ", "; f = false; os << x;} return os << "]";}
template<typename T> void debug(string s, T x) {cerr << s << " = " << x << "\n";}
template<typename T, typename... Args> void debug(string s, T x, Args... args) {cerr << s.substr(0, s.find(',')) << " = " << x << " | "; debug(s.substr(s.find(',') + 2), args...);}
template<typename T>
struct MinDeque {
int l = 0, r = 0;
deque<pair<T, int>> dq;
void push(T x) {
while (!dq.empty() && x <= dq.back().first)
dq.pop_back();
dq.emplace_back(x, r++);
}
void pop() {
assert(l < r);
if (dq.front().second == l++)
dq.pop_front();
}
T min() {
assert(!dq.empty());
return dq.front().first;
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin >> n;
vector<int> a(n);
for (int i=0; i<n; i++)
cin >> a[i];
vector<int> pref(n);
for (int i=0; i<n; i++)
pref[i] = a[i] + (i > 0 ? pref[i-1] : 0);
auto query = [&] (int l, int r) {
if (l <= r)
return pref[r] - (l > 0 ? pref[l-1] : 0);
else
return pref[n-1] - (l > 0 ? pref[l-1] : 0) + pref[r];
};
MinDeque<int> dq;
for (int i=0; i<=(n-1)/2; i++)
dq.push(query(i, (i + (n - 1) / 2) % n));
int ret = dq.min();
for (int i=1; i<n; i++) {
dq.push(query((i + (n - 1) / 2) % n, ((i + (n - 1) / 2) % n + (n - 1) / 2) % n));
dq.pop();
ret = max(ret, dq.min());
}
cout << ret << "\n";
return 0;
}
