#include <bits/stdc++.h>
#define d1(x) cout << #x << " : " << x << endl << flush
#define d2(x, y) cout << #x << " : " << x << " " << #y << " : " << y << endl << flush
#define d3(x, y, z) cout << #x << " : " << x << " " << #y << " : " << y << " " << #z << " : " << z << endl << flush
#define d4(x, y, z, a) cout << #x << " : " << x << " " << #y << " : " << y << " " << #z << " : " << z << " "<< #a << " : " << a << endl << flush
#define arr(x) array <ll, x>
#define ld long double
#define ll long long
#define int long long
#define pb push_back
#define endl '\n'
#define lc v << 1
#define rc v << 1 | 1
using namespace std;
const int INF = 1e18 + 24 + (34 / 10); // 34 ---> 35
const int MAXN = 1e6 + 24 + (34 / 10); // 34 ---> 35
int a[MAXN], ps[MAXN], ns;
struct nude{
int mn;
} sag[MAXN << 2];
void bld(int v = 1, int ls = 1, int rs = ns){
sag[v].mn = INF;
if(ls == rs)
return;
int m = (rs + ls) >> 1;
bld(lc, ls, m);
bld(rc, m + 1, rs);
}
void upd(int l, int r, int val, int v = 1, int ls = 1, int rs = ns){
if(l <= ls && rs <= r){
sag[v].mn = min(sag[v].mn, val);
return;
}
if(rs < l || r < ls)
return;
int m = (rs + ls) >> 1;
upd(l, r, val, lc, ls, m);
upd(l, r, val, rc, m + 1, rs);
}
int get(int ind, int v = 1, int ls = 1, int rs = ns){
if(ls == rs)
return sag[v].mn;
int m = (rs + ls) >> 1;
if(ind <= m)
return min(get(ind, lc, ls, m), sag[v].mn);
else
return min(get(ind, rc, m + 1, rs), sag[v].mn);
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n;
cin >> n;
ns = 1;
while(ns < (2 * n))
ns <<= 1;
for(int i = 1; i <= n; i++){
cin >> a[i];
a[i + n] = a[i];
}
for(int i = 1; i <= (2 * n); i++){
ps[i] = ps[i - 1] + a[i];
}
bld();
// d1(0);
for(int l = 1; l <= n; l++){
int r = (n + 1) / 2 + l - 1;
int sum = ps[r] - ps[l - 1];
upd(l, r, sum);
}
int ans = 0;
// d1(1);
for(int i = 1; i <= n; i++)
ans = max(ans, min(get(i), get(i + n)));
cout << ans << endl;
}
// Ey To Bahane! :_)))
// -------------<3------------- //
/*
Magasan dor shirini:
1. MAXN
2. Input style
3. index or value? Masale In Ast!
4. MOD
*/
