#include <bits/stdc++.h>

using namespace std;
using ll = long long;
template <typename T>
using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using Graph = vector<vector<int>>;

const ll INF = 1LL << 60;

template <class T>
void chmax(T& a, T b) {
    if (b > a) a = b;
}
template <class T>
void chmin(T& a, T b) {
    if (b < a) a = b;
}

template <typename T, typename S>
std::ostream& operator<<(std::ostream& os, const pair<T, S>& x) noexcept {
    return os << "(" << x.first << ", " << x.second << ")";
}

template <typename T>
void print_vector(vector<T> a) {
    cout << '[';
    for (int i = 0; i < a.size(); i++) {
        cout << a[i];
        if (i != a.size() - 1) {
            cout << ", ";
        }
    }
    cout << ']' << endl;
}

int main() {
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    ll N;
    cin >> N;
    vector<ll> A(2 * N), B(2 * N), X(N), Y(N);
    for (int i = 0; i < 2 * N; i++) {
        cin >> A[i];
    }
    for (int i = 0; i < 2 * N; i++) {
        cin >> B[i];
    }
    for (int i = 0; i < N; i++) {
        cin >> X[i];
    }
    for (int i = 0; i < N; i++) {
        cin >> Y[i];
    }
    vector<vector<ll>> dp(2 * N, vector<ll>(2, 0));
    dp[0][0] = A[0];
    dp[0][1] = B[0];
    for (int i = 1; i < 2 * N; i++) {
        ll a = A[i];
        ll b = B[i];
        if (i % 2 == 1) {
            ll x = X[i / 2];
            ll y = Y[i / 2];
            ll tmp0 = max(dp[i - 1][0] + x, dp[i - 1][1] + y);
            dp[i][0] = tmp0 + a;
            ll tmp1 = max(dp[i - 1][0] + y, dp[i - 1][1] + x);
            dp[i][1] = tmp1 + b;
        } else {
            ll tmp = max(dp[i - 1][0], dp[i - 1][1]);
            dp[i][0] = tmp + a;
            dp[i][1] = tmp + b;
        }
    }
    std::cout << max(dp[2 * N - 1][0], dp[2 * N - 1][1]) << "\n";
    return 0;
}