#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
const int NMAX = 5e5;
const int INF = 2e9;
int n, k;
int s, max_answer;
int answer[NMAX + 1];
int a[2 * NMAX + 1];
int sp[2 * NMAX + 1];
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for(int i = 1; i <= n; i++) {
cin >> a[i];
a[n + i] = a[i];
}
k = n / 2 + n % 2;
for(int i = 1; i <= 2 * n; i++) {
sp[i] = sp[i - 1] + a[i];
}
for(int i = 1; i <= n; i++) {
answer[i] = INF;
}
for(int i = k; i - k + 1 <= n; i++) {
int s_here = sp[i] - sp[i - k];
for(int j = i - k + 1; j <= i; j++) {
int pos = (j > n ? j - n : j);
answer[pos] = min(answer[pos], s_here);
}
}
for(int i = 1; i <= n; i++) {
max_answer = max(max_answer, answer[i]);
}
cout << max_answer << '\n';
return 0;
}
/*
1 2 3 4 5 1 2 3 4 5
*/
