#pragma region Macros

#include <bits/extc++.h>
// #include <bits/stdc++.h>
using namespace std;
using namespace __gnu_pbds;
// using namespace __gnu_cxx;
// #include <atcoder/all>
// using namespace atcoder;

// #include <boost/multiprecision/cpp_int.hpp>
// namespace mp = boost::multiprecision;
// using Bint = mp::cpp_int;

#define TO_STRING(var) # var
#define pb emplace_back
#define int ll
#define endl '\n'

using ll = long long;
using ld = long double;
const ld PI = acos(-1);
const ld EPS = 1e-10;
const ll INFL = 1LL << 61;
const int MOD = 998244353;
// const int MOD = 1000000007;

__attribute__((constructor))
void constructor() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
}

int modpow(int x, int N, int mod) {
    int ret = 1;
    while (N > 0) {
        if (N % 2 == 1) ret = ret * x % mod;
        x = x * x % mod;
        N /= 2;
    }
    return ret;
}

int ceil(int x, int y) { return (x > 0 ? (x + y - 1) / y : x / y); }

#pragma endregion

signed main() {
    int N;
    cin >> N;
    vector<int> A(2 * N);
    for (int i = 0; i < 2 * N; i++) cin >> A[i];
    vector<int> B(2 * N);
    for (int i = 0; i < 2 * N; i++) cin >> B[i];
    vector<int> X(N);
    for (int i = 0; i < N; i++) cin >> X[i];
    vector<int> Y(N);
    for (int i = 0; i < N; i++) cin >> Y[i];

    vector<vector<int>> dp(2 * N, vector<int>(2));
    dp[0][0] = A[0];
    dp[0][1] = B[0];
    for (int i = 1; i < 2 * N; i++) {
        if (i % 2) { // 偶数番目なら
            dp[i][0] = max(dp[i - 1][0] + X[i / 2], dp[i - 1][1] + Y[i / 2]) + A[i];
            dp[i][1] = max(dp[i - 1][1] + X[i / 2], dp[i - 1][0] + Y[i / 2]) + B[i];
        } else {
            dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]) + A[i];
            dp[i][1] = max(dp[i - 1][0], dp[i - 1][1]) + B[i];
        }
    }
    cout << max(dp[2 * N - 1][0], dp[2 * N - 1][1]) << endl;
}