#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = 1001001001;
const ll LINF = 1001002003004005006ll;
//const int mod = 1000000007;
//const int mod = 998244353;

int main()
{
  ll n;
  cin >> n;
  ll n2 = 2*n;
  vector<ll> a(n2), b(n2), x(n), y(n);
  rep(i, 0, n2) cin >> a[i];
  rep(i, 0, n2) cin >> b[i];
  rep(i, 0, n) cin >> x[i];
  rep(i, 0, n) cin >> y[i];
  vector<ll> dp(2);
  rep(i, 0, n2) {
    vector<ll> p = dp;
    dp[0] = max(p[1] + a[i], p[0] + a[i]);
    if (i&1) dp[0] = max({dp[0], p[0] + a[i] + x[i/2], p[1] + a[i] + y[i/2]});
    dp[1] = max(p[0] + b[i], p[1] + b[i]);
    if (i&1) dp[1] = max({dp[1], p[0] + b[i] + y[i/2], p[1] + b[i] + x[i/2]});
  }
  cout << max(dp[0], dp[1]) << endl;
  return 0;
}