#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define pb push_back
#define st first
#define nd second
#define pq priority_queue
#define all(x) begin(x), end(x)
#include <time.h>
#include <cmath>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int i_inf = 1e9;
const ll inf = 1e18;
const ll mod = 1000000007;
const ld eps = 1e-13;
const ld pi = 3.14159265359;
mt19937 _rand(time(NULL));
clock_t timer = clock();
const int mxn = 5e5;
void solve(){
int n;
cin >> n;
int a[2*n];
fr(i, 0, n){
cin >> a[i];
a[i+n] = a[i];
}
int len = (n+1)/2;
n*=2;
int pre[n];
pre[0] = a[0];
fr(i, 1, n){
pre[i] = pre[i-1]+a[i];
}
int sum[n];
memset(sum, 0, sizeof(sum));
fr(i, len-1, n){
int s = pre[i];
if(i-len >= 0) s -= pre[i-len];
sum[i-len+1] = s;
}
int ans = 0;
pq<pii> Q;
fr(i, 0, n){
Q.push({-sum[i], i});
while(!Q.empty() && Q.top().nd <= i-len) Q.pop();
if(i >= len-1) ans = max(ans, - Q.top().st);
}
cout<<ans<<endl;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
solve();
}
