#include <cstdio>
#include <iostream>
#include <vector>
#include <list>
#include <string>
#include <set>
#include <map>
#include <algorithm>
#include <fstream>
#include <cmath>
#include <queue>
#include <stack>
#include <cassert>
#include <cstring>
#include <climits>
#include <functional>
#include <cstdlib>
#include <complex>
#include <array>
#include <iomanip>
#include <bitset>
#include <unordered_map>
#include <random>
#define fileIO(name) if(fopen(name".in", "r")) {freopen(name".in", "r", stdin); freopen(name".out", "w", stdout);}
using namespace std;
const int MAXN = 1e6 + 111;
using ll = long long;
const int P = 31;
const ll mod1 = 1e9 + 7;
const ll mod2 = 998244353;
using ld = long double;
const ld EPS = 1e-5;
using pii = pair<int, int>;
typedef complex<ll> Point;
int n;
int v[MAXN];
ll ans;
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
//fileIO("cardgame");
cin >> n;
for (int i = 1; i <= n; i++)
cin >> v[i];
for (int i = n + 1; i <= 2 * n; i++)
v[i] = v[i - n];
for (int i = 1; i <= 2 * n; i++)
v[i] = v[i - 1] + v[i];
vector<ll> ret(n + 1, 1e18);
int SZ = (n + 1) / 2;
multiset<ll> vals;
for (int i = 1; i <= 2 * n; i++)
{
if (i + SZ - 1 <= 2 * n)
vals.insert(v[i + SZ - 1] - v[i - 1]);
if (i > SZ)
vals.erase(vals.find(v[i-1] - v[i-SZ-1]));
int prv = ((i - 1) % n) + 1;
ret[prv] = min(ret[prv], *vals.begin());
}
for (int i = 1; i <= n; i++)
ans = max(ans, ret[i]);
cout << ans << '\n';
return 0;
}
