#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define endl "\n"
const int MOD = 1e9+7;
const int inf = 1e9;
const int linf = 1e18;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
// -------------------------------------------------- Main Code --------------------------------------------------
void sol() {
int n; cin >> n;
int mid = (n+1)/2;
int arr[2*n];
for (int i = 0; i < n; i++) {cin >> arr[i]; arr[i+n] = arr[i];}
for (int i = 1; i < 2*n; i++) arr[i] += arr[i-1];
multiset<int> st;
for (int i = mid-1; i < n-1; i++) { int pSum = arr[i]; if (i >= mid) pSum -= arr[i-mid]; st.insert(pSum);}
int ans = *st.begin();
for (int i = n-1; i < 2*n; i++) {
int idx = i-mid;
if (idx >= mid-1) st.erase(st.find(arr[idx]-(idx >= mid?arr[idx-mid]:0)));
int pSum = arr[i] - arr[i-mid];
st.insert(pSum);
ans = max(ans, *st.begin());
}
cout << ans << endl;
}
signed main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
sol();
}
return 0;
}
