#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> a, b;
vector<vector<int>> g;
vector<vector<long long>> dp;
void dfs (int cur, int par) {
  dp[cur][0] = a[cur];
  vector<long long> v;
  for (int child : g[cur]) if (child != par) {
    dfs (child, cur);
    dp[cur][0] += max(dp[child][0], dp[child][1]);
    v.push_back(dp[child][1]);
  }
  dp[cur][1] = 0;
  for (int child : g[cur]) if (child != par) {
    dp[cur][1] += max(dp[child][0], dp[child][1] + b[cur] + b[child]);
  }
}
signed main() { 
  ios::sync_with_stdio(false); cin.tie(0);
  cin >> n;
  a = vector<int>(n);
  b = a;
  g = vector<vector<int>>(n);
  dp = vector<vector<long long>>(n, vector<long long>(2));
  for (auto& x : a) cin >> x;
  for (auto& x : b) cin >> x;
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    v--;
    u--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  dfs(0, -1);
  cout << max(dp[0][0], dp[0][1]) << endl;
  return 0;
}