#include <bits/stdc++.h>
using namespace std;
#define int long long
const int MAXN = 5e5+2;
int n;
int l[2 * MAXN], r[2 * MAXN], val[2 * MAXN];
int sums[MAXN];
int curent = 0;
void build(int now = 1){
if (now < n) {
build(now * 2);
build(now * 2 + 1);
l[now] = l[now * 2];
r[now] = r[now * 2 + 1];
val[now] = min(val[now * 2], val[now * 2 + 1]);
} else {
l[now] = curent;
r[now] = curent;
val[now] = sums[curent++];
}
}
int query(int left, int right, int now = 1){
if (right < l[now] || r[now] < left) {
return INT32_MAX; // <-- small fix: use INT32_MAX instead of INT_MAX
}
if (left <= l[now] && r[now] <= right) {
return val[now];
}
return min(query(left, right, now * 2), query(left, right, now * 2 + 1));
}
signed main(){
cin >> n;
vector<int> numere(n);
int sum = 0, half = (n + 1) / 2;
for (int i = 0; i < n; i++) {
cin >> numere[i];
if (i < half) {
sum += numere[i];
}
}
for (int i = 0; i <= n; i++) {
sums[i % n] = sum;
sum += numere[(i + half) % n];
sum -= numere[i % n];
}
build();
int ans = 0;
for (int i = 0; i < n; i++) {
int left = (i - half + 1 + n) % n;
int right = i;
if (right < left) {
ans = max(ans, min(query(0, right), query(left, n - 1)));
} else {
ans = max(ans, query(left, right));
}
}
cout << ans;
}
