/**
* author: wxhtzdy
* created: 20.07.2022 16:47:00
**/
#include <bits/stdc++.h>
using namespace std;
// usage:
// auto fun = [&](int i, int j) { return min(i, j); };
// SparseTable<int, decltype(fun)> st(a, fun);
// or:
// SparseTable<int> st(a, [&](int i, int j) { return min(i, j); });
template <typename T, class F = function<T(const T&, const T&)>>
class SparseTable {
public:
int n;
vector<vector<T>> mat;
F func;
SparseTable(const vector<T>& a, const F& f) : func(f) {
n = static_cast<int>(a.size());
int max_log = 32 - __builtin_clz(n);
mat.resize(max_log);
mat[0] = a;
for (int j = 1; j < max_log; j++) {
mat[j].resize(n - (1 << j) + 1);
for (int i = 0; i <= n - (1 << j); i++) {
mat[j][i] = func(mat[j - 1][i], mat[j - 1][i + (1 << (j - 1))]);
}
}
}
T get(int from, int to) const {
assert(0 <= from && from <= to && to <= n - 1);
int lg = 32 - __builtin_clz(to - from + 1) - 1;
return func(mat[lg][from], mat[lg][to - (1 << lg) + 1]);
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
vector<long long> pref(2 * n + 1);
for (int i = 0; i < 2 * n; i++) {
pref[i + 1] = pref[i] + a[i % n];
}
int moves = (n + 1) / 2;
vector<long long> val(n + 1);
for (int i = 1; i <= n; i++) {
val[i] = pref[i + moves - 1] - pref[i - 1];
}
SparseTable<long long> st(val, [&](long long a, long long b) { return min(a, b); });
long long ans = 0;
for (int i = 1; i <= n; i++) {
long long mn;
if (i - moves >= 0) {
mn = st.get(i - moves + 1, i);
} else {
mn = min(st.get(1, i), st.get(n - (moves - i) + 1, n));
}
ans = max(ans, mn);
}
cout << ans << '\n';
return 0;
}
