#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic pop
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  VI a(n);
  rep(i, n) cin >> a[i];
  constexpr ll INF = 1002003004005006007;
  if (n % 2) {
    int m = n / 2;
    ll ans = INF;
    ll now = accumulate(a.begin(), a.begin() + m, 0LL);
    rep(i, m + 1) {
      now += a[i + m];
      chmin(ans, now);
      now -= a[i];
    }
    cout << ans << '\n';
    return 0;
  }
  int m = n / 2;
  VL accmf(n + 1, INF), accmb(n + 1, INF), accm1f(n + 1, INF), accm1b(n + 1);
  {
    ll now = accumulate(a.begin(), a.begin() + m - 1, 0LL);
    ll acc = INF;
    for(int i = 0; i + m - 1 < n; i++) {
      now += a[i + m - 1];
      chmin(acc, now);
      accmf[i] = acc;
      now -= a[i];
    }
  }
  {
    ll now = accumulate(a.end() - (m - 1), a.end(), 0LL);
    ll acc = INF;
    for(int i = n - m; i >= 0; i--) {
      now += a[i];
      chmin(acc, now);
      accmb[i] = acc;
      now -= a[i + m - 1];
    }
  }
  m++;
  {
    ll now = accumulate(a.begin(), a.begin() + m - 1, 0LL);
    ll acc = INF;
    for(int i = 0; i + m - 1 < n; i++) {
      now += a[i + m - 1];
      chmin(acc, now);
      accm1f[i] = acc;
      now -= a[i];
    }
  }
  {
    ll now = accumulate(a.end() - (m - 1), a.end(), 0LL);
    ll acc = INF;
    for(int i = n - m; i >= 0; i--) {
      now += a[i];
      chmin(acc, now);
      accm1b[i] = acc;
      now -= a[i + m - 1];
    }
  }
  m--;
  ll ans = 0;
  for(int i = 0; i < n - 1; i++) {
    if (i < m - 1) {
      chmax(ans, min(accm1f[i], accmb[i + 2]));
    } else if (i == m - 1) {
      chmax(ans, accm1f[i]);
    } else {
      chmax(ans, min(accmf[i - m], accm1b[i - m + 1]));
    }
  }
  cout << ans << '\n';
}