#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int inf = 1e9;
void solve(){
int n; cin >> n;
vector<int> p(n);
for(int i = 0; i < n; i ++) cin >> p[i];
int ans = 0;
for(int i = 1; i < n; i ++){
p[i] += p[i - 1];
}
auto get = [&](int l, int r)->int{
if(l > r){
return p[r] + p[n - 1] - (l ? p[l - 1] : 0);
}
return p[r] - (l ? p[l - 1] : 0);
};
int k = (n + 1) / 2;
for(int i = 0; i < n; i ++){
int mn = inf;
for(int j = i; j < i + k; j ++){
int r = j % k;
int l = ((r - k + 1) % n + n) % n;
mn = min(mn, get(l, r));
}
ans = max(ans, mn);
if(n > 5000) break;
}
cout << ans;
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
int testcases = 1;
while(testcases --){
solve();
if(testcases) cout << '\n';
#ifdef LOCAL
else cout << '\n';
cout << "__________________________" << endl;
#endif
}
return 0;
}
