#include <bits/extc++.h>

template <class F>
struct y_combinator : private F {
  y_combinator(F f) : F(f) {}
  template <class... Args>
  decltype(auto) operator()(Args&&... args) const {
    return F::operator()(*this, std::forward<Args>(args)...);
  }
};

int main() {
  using namespace std;
  cin.tie(nullptr)->sync_with_stdio(false);
  int n;
  cin >> n;
  vector<int> a(n), b(n);
  for (auto&& e : a) cin >> e;
  for (auto&& e : b) cin >> e;
  vector<vector<int>> g(n);
  for (int _ = n - 1; _--;) {
    int u, v;
    cin >> u >> v;
    --u, --v;
    g[u].push_back(v);
    g[v].push_back(u);
  }

  // vertex v -> -a[v]
  // edge uv -> b[u] + b[v]

  vector<array<int64_t, 2>> dp(n);
  y_combinator([&](auto&& self, int v, int p) -> void {
    dp[v] = {a[v], 0};
    for (int u : g[v]) {
      if (u == p) continue;
      self(u, v);
      array<int64_t, 2> new_dp;
      new_dp.fill(-1e18);
      for (int x : {0, 1})
        for (int y : {0, 1})
          new_dp[x] =
              max(new_dp[x], dp[v][x] + dp[u][y] + x * y * (b[v] + b[u]));
      swap(dp[v], new_dp);
    }
  })(0, -1);

  cout << max(dp[0][0], dp[0][1]) << '\n';
}