#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
//#define int long long
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
struct SegTree {
int n;
vector<ll> tree, lazy;
SegTree(int _n) : n(_n), tree(4*_n+5, 1e18), lazy(4*_n+5, 1e18) {}
void push(int u, int tl, int tr) {
if(lazy[u] == 1e18) return ;
tree[u] = min(tree[u], lazy[u]);
if(tl != tr) {
lazy[2*u] = min(lazy[u], lazy[2*u+1]);
lazy[2*u+1] = min(lazy[u], lazy[2*u+1]);
}
lazy[u] = 1e18;
}
void update(int u, int tl, int tr, int l, int r, ll v) {
push(u, tl, tr);
if(tl > tr || l > tr || tl > r) return ;
if(l <= tl && tr <= r) {
lazy[u] = min(lazy[u], v);
push(u, tl, tr);
return ;
}
int tm = (tl + tr) / 2;
update(2*u, tl, tm, l, r, v);
update(2*u+1, tm+1, tr, l, r, v);
tree[u] = min(tree[2*u], tree[2*u+1]);
}
ll query(int u, int tl, int tr, int l, int r) {
if(tl > tr || l > tr || tl > r) return 1e18;
push(u, tl, tr);
if(l <= tl && tr <= r) return tree[u];
int tm = (tl + tr) / 2;
return min(query(2*u, tl, tm, l, r), query(2*u+1, tm+1, tr, l, r));
}
void update(int l, int r, ll v) { update(1, 0, n-1, l, r, v); }
ll query(int l, int r) { return query(1, 0, n-1, l, r); }
};
signed main() {
int n;
cin >> n;
vector<int> v(n+1);
for(int i=1; i<=n; i++) cin >> v[i];
for(int i=1; i<=n; i++) v.push_back(v[i]);
vector<ll> pref(2*n+1);
for(int i=1; i<=2*n; i++) pref[i] = pref[i-1] + v[i];
SegTree tree(n+1);
int len = (n + 1) / 2;
for(int i=1; i<=n; i++) {
ll val = pref[i+len-1] - pref[i-1];
if(i+len-1 <= n) tree.update(i, i+len-1, val);
else {
tree.update(i, n, val);
tree.update(1, i+len-1-n, val);
}
}
ll ans = 0;
for(int i=1; i<=n; i++) ans = max(ans, tree.query(i, i));
cout << ans << '\n';
return 0;
}
