#include <bits/stdc++.h>
using namespace std;
#define rep(i,s,e) for (ll i = s; i <= e; ++i)
#define rrep(i,s,e) for (ll i = s; i >= e; --i)
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define all(a) a.begin(), a.end()
typedef long long ll;
typedef pair<ll, ll> ii;
typedef vector<ii> vii;
typedef vector<ll> vi;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
ll n; cin >> n;
ll w[n], k = (n+1)/2, s = 0;
rep (i,0,n-1) cin >> w[i];
rep (i,0,k-1) s += w[i];
vi segs;
rep (i,0,n-1) {
segs.pb(s);
s -= w[i];
s += w[(i+k)%n];
}
multiset<ll> st;
rep (i,0,k-1) st.insert(segs[i]);
ll ans = 0;
rep (i,0,n-1) {
ans = max(ans, *st.begin());
st.erase(st.find(segs[i]));
st.insert(segs[(i+k)%n]);
}
cout << ans << "\n";
return 0;
}
