#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
#define FOR(i, x, y) for(ll i=x; i<y; i++)
#define FORNEG(i, x, y) for(ll i=x; i>y; i--)
#define fast() ios_base::sync_with_stdio(false);cin.tie(NULL)
ll n;
vector<ll> sussies;
vector<ll> realsus;
multiset<ll> imp;
ll ans = -1;
int main(){
cin >> n;
FOR(i,0,n){
ll temp;
cin >> temp;
sussies.push_back(temp);
}
FOR(i,0,n){
sussies.push_back(sussies[i]);
}
ll k = (n+1)/2;
ll cur = 0;
FOR(i,0,k) cur += sussies[i];
realsus.push_back(cur);
FOR(i,1,n){
cur -= sussies[i-1];
cur += sussies[i+k-1];
realsus.push_back(cur);
}
ll temp = realsus.size();
FOR(i,0,temp) realsus.push_back(realsus[i]);
FOR(i,0,k) imp.insert(realsus[i]);
ans = max(ans, *imp.begin());
FOR(i,1,n){
imp.erase(imp.find(realsus[i-1]));
imp.insert(realsus[i+k-1]);
ans = max(ans, *imp.begin());
}
cout << ans << endl;
}
