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

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;
	vector<int> a(n), b(n), c(n);
	for (int &x : a)
		cin >> x;
	for (int &x : b)
		cin >> x;
	for (int &x : c)
		cin >> x;

	auto check = [&](long long x) {
		set<long long> S;
		long long offset = 0;

		S.emplace(b[0]);

		for (int i = 0; i < n; i++) {
			offset += a[i] + c[i];

			if (i > 0) {
				offset -= c[i - 1];
			}

			if (*S.rbegin() + offset >= x && i + 1 < n) {
				S.emplace(b[i + 1] - offset + c[i]);
			}
		}

		return *S.rbegin() + offset >= x;
	};
		
	long long l = -1e18L, r = +1e18L;
	while (r - l > 1) {
		long long m = (l + r) >> 1;

		if (check(m))
			l = m;
		else
			r = m;
	}

	cout << l << '\n';

	return 0;
}