#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (int)n; i++)
using ll = long long;
const ll INF = 1e17;

int main(){
  int n;
  cin >> n;
  vector<ll> a(n), b(n);
  rep(i,n) cin >> a[i];
  rep(i,n) cin >> b[i];
  vector<vector<int>> g(n);
  rep(i,n-1) {
    int u, v;
    cin >> u >> v;
    u--; v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }  
  vector<ll> dp1(n,-INF);
  vector<ll> dp2(n,-INF);
  auto dfs = [&](auto self, int u, int p) -> void {
    ll del = a[u], res = 0;
    for(int to : g[u]) {
      if(to != p) {
        self(self,to,u);
        del += max(dp1[to],dp2[to]);
        res += max(dp1[to]+b[u]+b[to],dp2[to]);
      }
    }
    dp1[u] = res;
    dp2[u] = del;
  };
  dfs(dfs,0,-1);
  cout << max(dp1[0],dp2[0]) << endl;
  return 0;
}