#include <algorithm>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <iostream>
#include <numeric>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <functional>
#include <iomanip>
using namespace std;
using ll = long long;

class range {private: struct I{int x;int operator*(){return x;}bool operator!=(I& lhs){return x<lhs.x;}void operator++(){++x;}};I i,n;
public:range(int n_):i({0}),n({n_}){}range(int i_,int n_):i({i_}),n({n_}){}I& begin(){return i;}I& end(){return n;}};

template<typename T, typename U> ostream& operator<<(ostream& os, const pair<T, U>& p){ return os << "{" << p.first << ", " << p.second << "}"; }
template<typename T> ostream& operator<<(ostream& os, const vector<T>& obj) { os << "{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }
template<typename T> ostream& operator<<(ostream& os, const set<T>& obj) { os << "set{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }
template<typename T, typename U> ostream& operator<<(ostream& os, const map<T, U>& obj) { os << "map{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }
template<typename T> void take(vector<T>& vec, int n) { vec.resize(n); for (int i = 0; i < n; ++i) cin >> vec[i]; }

#ifdef ONLINE_JUDGE
#define dump(expr) ;
#else
#define dump(expr) { cerr << "\033[33m#L" << __LINE__ << ": " << expr << "\033[39m" << endl; }
#endif

using EdgeCost = ll;
struct E {
  int fr, to, eid;
  EdgeCost cost;
  E(int fr_, int to_, int eid_, EdgeCost cost_) : fr(fr_), to(to_), eid(eid_), cost(cost_) {}
  friend ostream &operator<<(ostream &os, const E &e) { os << "(" << e.fr << " -> " << e.to << ")"; return os; }
};
using V = vector<E>;
struct G {
  int n, e_count;
  vector<V> adj;
  vector<V> rev;
  G(int n_) : n(n_), e_count(0), adj(n), rev(n) {}

  void add_directed_edge(int fr, int to, EdgeCost cost = (EdgeCost)1) {
    int eid = e_count;
    adj[fr].push_back(E(fr, to, eid, cost));
    rev[to].push_back(E(fr, to, eid, cost));
    e_count++;
  }

  void add_undirected_edge(int fr, int to, EdgeCost cost = (EdgeCost)1) {
    int eid = e_count;
    adj[fr].push_back(E(fr, to, eid, cost));
    rev[to].push_back(E(fr, to, eid, cost));
    adj[to].push_back(E(to, fr, eid, cost));
    rev[fr].push_back(E(to, fr, eid, cost));
    e_count++;
  }
};

namespace solver {

template<typename T1, typename T2> struct In2 {
  T1 a; T2 b;
  friend std::istream& operator>>(std::istream& is, In2& obj) { T1 t1; T2 t2; is >> t1 >> t2; obj = {t1, t2}; return is; }
};

template<typename T1, typename T2, typename T3> struct In3 {
  T1 a; T2 b; T3 c;
  friend std::istream& operator>>(std::istream& is, In3& obj) { T1 t1; T2 t2; T3 t3; is >> t1 >> t2 >> t3; obj = {t1, t2, t3}; return is; }
};

int n;
vector<ll> as, bs;
vector<In2<ll, ll>> vt;

void read() {
  cin >> n;
  take(as, n);
  take(bs, n);
  take(vt, n - 1);
}


G g(0);
ll dp[100010][2];
void dfs(ll x, ll par) {
  for (int i : range(2)) {
    for (auto e : g.adj[x]) if (e.to != par) dfs(e.to, x);

    ll score = 0;
    if (i == 0) score += as[x - 1];
    for (auto e : g.adj[x]) if (e.to != par) {
      ll best = -1LL << 60;
      for (int j : range(2)) {
        ll gain = dp[e.to][j];
        if (i && j) gain += bs[x - 1] + bs[e.to - 1];
        best = max(best, gain);
      }
      score += best;
    }
    dp[x][i] = score;
  }
}


using RetType = ll;

RetType run() {
  g = G(n + 1);
  for (auto p : vt) g.add_undirected_edge(p.a, p.b);

  dfs(1, -1);
  return max(dp[1][0], dp[1][1]);
}

}  // namespace

template <typename F>
void run(F f) { if constexpr (std::is_same_v<decltype(f()), void>) f(); else cout << f() << endl; }

int main(int argc, char** argv) {
  cerr << fixed << setprecision(12);
  cout << fixed << setprecision(12);
  int testcase = 1;
  if (argc > 1) testcase = atoi(argv[1]);
  while (testcase--) {
    solver::read();
  }
  run(solver::run);
}