#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <utility>
#define FAST_IO ios::sync_with_stdio(false);cin.tie(0);
#define pb push_back
#define all(x) begin(x), end(x)
#define space " "
#define TEST_CASES int a; cin >> a; for (int i = 0; i < a; i++) {solve(); cout << endl;}
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
void solve() {
int n; cin >> n;
vector<int> vec(n);
for (int i = 0; i < n; i++) {
cin >> vec[i];
}
vector<int> pref(n);
for (int i = 0; i < n; i++) {
pref[i] = vec[i];
if (i) {
pref[i] += pref[i - 1];
}
}
int res = 0;
for (int i = 0; i < n; i++) {
int left;
if (i < (n - 1) / 2) {
left = pref[i] + pref[n - 1] - pref[n - 1 - (n - 1) / 2 + i];
}
else {
left = pref[i] - (i == (n - 1) / 2 ? 0 : pref[i - (n - 1) / 2 - 1]);
}
int right;
if (i + (n + 1) / 2 - 1 >= n) {
right = pref.back() - pref[i - 1] + pref[(n + 1) / 2 - (n - i) - 1];
}
else {
right = pref[i + (n + 1) / 2 - 1] - (i ? pref[i - 1] : 0);
}
res = max(res, min(left, right));
}
cout << res;
}
int main() {
FAST_IO;
//freopen("fortmoo.in", "r", stdin);
//freopen("fortmoo.out", "w", stdout);
//TEST_CASES;
solve(); //cout << endl;
/*int a; cin >> a;
for (int i = 1; i <= a; i++){
cout << "Case #" << i << ": ";
solve();
cout << endl;
}*/
}
