#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define rrep2(ri,x,n) for(int ri = (int)(n-1); ri >= (int)(x); ri--)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(x) x.begin(), x.end()
using ll = long long;
using namespace std;

const ll INF = 9e18;

void dfs(vector<vector<int>> &tree, vector<ll> &dp0, vector<ll> &dp1, vector<int> &a, vector<int> &b, int now, int bf){
  dp0.at(now) = a.at(now);
  dp1.at(now) = 0;
  for(auto nx : tree.at(now)){
    if(nx == bf) continue;
    if(dp0.at(nx) == -INF) dfs(tree, dp0, dp1, a, b, nx, now);
    dp0.at(now) += max(dp0.at(nx), dp1.at(nx));
    dp1.at(now) += max(dp0.at(nx), dp1.at(nx)+b.at(now)+b.at(nx));
  }
}

int main(){
  int n;
  cin >> n;
  vector<int> a(n);
  rep(i, n) cin >> a.at(i);
  vector<int> b(n);
  rep(i, n) cin >> b.at(i);
  vector<vector<int>> tree(n, vector<int>());
  rep(i, n-1){
    int a, b;
    cin >> a >> b;
    a--; b--;
    tree.at(a).push_back(b);
    tree.at(b).push_back(a);
  }
  vector<ll> dp0(n, -INF), dp1(n, -INF);
  dfs(tree, dp0, dp1, a, b, 0, -1);
  cout << max(dp0.at(0), dp1.at(0)) << endl;
  return 0;
}