#include <bits/stdc++.h>
using namespace std;

int main() {
  cin.tie(0), ios::sync_with_stdio(0);

  int n;
  cin >> n;

  vector<int> a(n), b(n);
  for (int& ai : a) cin >> ai;
  for (int& bi : b) cin >> bi;

  vector<int> pref_a(n + 1), pref_b(n + 1), suff_a(n + 1), suff_b(n + 1);
  partial_sum(a.begin(), a.end(), pref_a.begin() + 1);
  partial_sum(a.rbegin(), a.rend(), suff_a.rbegin() + 1);
  partial_sum(b.begin(), b.end(), pref_b.begin() + 1);
  partial_sum(b.rbegin(), b.rend(), suff_b.rbegin() + 1);

  int best = INT_MAX;
  for (int i = 0; i <= n; i++) {
    best = min({best, pref_a[i] + suff_b[i], pref_b[i] + suff_a[i]});
  }
  cout << best;
}