#include <bits/stdc++.h>
#define int long long
using namespace std;
using ll = long long;

const int N = 2e5 + 11;
int a[N], b[N], c[N], p[N];
int n; 


bool ok(int C){
    int cmin = b[0];
    for (int i = 1; i <= n; i++) {
        if (c[i] + p[i] >= C - cmin) {
            cmin = max(cmin, b[i] - p[i]);
            if (i == n) return true;
        }
    }
    return false;
}

void solve() {
    cin >> n;
    for (int i = 0; i < n; i++) cin >> a[i];
    for (int i = 0; i < n; i++) p[i + 1] = p[i] + a[i];
    for (int i = 0; i < n; i++) cin >> b[i];
    for (int i = 1; i <= n; i++) cin >> c[i];

    int l = 0, r = 1LL << 60;
    while (l != r) {
        int mid = (l + r + 1) / 2;
        if (ok(mid)) l = mid;
        else r = mid - 1;
    }
    cout << l << '\n';
}

int32_t main() {
#ifndef LOCAL
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
#endif
    int T = 1;
    // cin >> T;
    while (T--) solve();
    return 0;
}