#include"bits/stdc++.h"
using namespace std;
typedef long long ll;
int main(){
ll n; cin >> n;
vector<ll> a(2 * n + 1);
a[0] = 0;
multiset<ll> d;
ll S = (n + 1) / 2;
for (ll i = 1; i <= n; i++){
cin >> a[i]; a[n + i] = a[i];
}
for (ll i = 1; i <= 2 * n; i++) a[i] += a[i - 1];
ll res = 0;
vector<ll> c(n + 1, 0);
for (ll i = 1; i <= 2 * n; i++){
if (i + S - 1 <= 2 * n) d.insert(a[i + S - 1] - a[i - 1]);
if (i > S) d.erase(d.find(a[i - 1] - a[i - 1 - S]));
ll tempt = ((i - 1) % n) + 1;
c[tempt] = min(c[tempt], *c.begin());
}
for (ll i = 1; i <= n; i++) res=max(res, c[i]);
cout << res;
}
