//: // ////: /// / : //// / :
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pll;
#define all(x) (x).begin(),(x).end()
#define X first
#define Y second
#define sep ' '
#define endl '\n'
#define debug(x) cerr << #x << ": " << x << endl;
const ll MAXN = 1e6 + 10;
const ll INF = 1e9 + 10;
int S[MAXN], A[MAXN], n, t, ans[MAXN];
deque<pll> dq;
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n;
t = (n + 1) / 2;
for (int i = 0; i < n; i++) {
cin >> A[i];
if (i < t) S[0] += A[i];
ans[i] = INF;
}
for (int i = 1; i < n; i++)
S[i] = S[i - 1] - A[i - 1] + A[(i + t - 1) % n];
for (int j = 0; j < 2 * n; j++) {
int i = j % n;
pll e = {S[i], j};
while (!dq.empty() && e < dq.back()) dq.pop_back();
dq.push_back(e);
if (j - dq.front().Y >= t) dq.pop_front();
ans[i] = min(ans[i], dq.front().X);
}
cout << *max_element(ans, ans + n) << endl;
return 0;
}
