#include <bits/stdc++.h>
#include <experimental/random>
#include <random>
//#include <ext/pb_ds/assoc_container.hpp>
//using namespace __gnu_pbds;
using namespace std;
using ld = long double;
using ll = long long;
const ll INF = 1e18, MOD = 1e9 + 7;
void solve();
signed main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ios::sync_with_stdio(false);
cin.tie(0);
int q = 1;
//cin >> q;
while (q--) {
solve();
}
}
void solve() {
ll n; cin >> n;
vector<ll> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
for (int i = 0; i < n; i++) {
a.push_back(a[i]);
}
vector<ll> b(n);
for (int i = 0; i < n; i++) {
cin >> b[i];
}
for (int i = 0; i < n; i++) {
b.push_back(b[i]);
}
vector<ll> pref(2 * n);
for (int i = 1; i < 2 * n; i++) {
pref[i] = pref[i - 1] + b[i - 1];
}
vector<ll> val(2 * n);
for (int i = 0; i < 2 * n; i++) {
val[i] = a[i] - pref[i];
}
vector<ll> mx(2 * n);
deque<ll> idx;
for (int i = 0; i < 2 * n; i++) {
while (!idx.empty() && val[idx.back()] < val[i]) {
idx.pop_back();
}
idx.push_back(i);
if (idx.front() == i - n) {
idx.pop_front();
}
mx[i] = val[idx.front()];
}
ll ans = INF;
for (ll i = n - 1; i < 2 * n; i++) {
ans = min(ans, mx[i] + pref[i - n + 1]);
}
cout << max(0ll, ans);
}
