#include <bits/stdc++.h>
using namespace std;
const long long INFll = (long long) 1e18 + 10;
const int INFii = (int) 1e9 + 10;
typedef long long ll;
typedef int ii;
typedef long double dbl;
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
#define maxn 1050000
ii n, v[maxn], r[maxn], ps[maxn];
int main() {
ios::sync_with_stdio(false); cin.tie(0);
//freopen("in.in", "r", stdin);
//freopen("out.out", "w", stdout);
cin >> n;
for(ii i = 1; i <= n; i++) {
cin >> v[i];
v[i+n] = v[i];
}
for(ii i = 1; i <= 2*n; i++) {
ps[i] = ps[i-1] + v[i];
r[i] = INFii;
}
ii ans = 0;
ii sz = (n+1)/2;
//cout << sz << endl;
for(ii i = 1; i <= 2*n; i++) {
//cout << i << endl;
for(ii j = 0; j < sz; j++) {
if(i+j <= 2*n && i-sz+j >= 0) {
//cout << " " << j << " " << i-sz+j+1 << " " << i+j << " " << ps[i+j] - ps[i-sz+j] << endl;
r[i] = min(r[i],ps[i+j] - ps[i-sz+j]);
}
}
}
for(ii i = 1; i <= n; i++) {
ans = max(ans, min(r[i],r[i+n]));
//cout << i << " " << min(r[i],r[i+n]) << endl;
}
cout << ans << endl;
}
