#include<bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint=modint998244353; //1000000007;
using ll=long long;
using pp=pair<int,int>;
#define sr string 
#define vc vector
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define pque priority_queue
#define bpc(a) __builtin_popcount(a)
int main(){
  int n;cin>>n;
  vc<ll>x(n),y(n); rep(i,n)cin>>x[i]; rep(i,n)cin>>y[i];
  vc v(n,vc<int>(0));
  rep(i,n-1){
    int a,b;cin>>a>>b;a--;b--;
    v[a].pb(b);v[b].pb(a);
  }
  auto f=[&](auto f,int a,int p)->pair<ll,ll>{
    pair<ll,ll>res={x[a],0};
    for(auto au:v[a])if(au!=p){
      auto now=f(f,au,a);
      res.fi+=max(now.se,now.fi);
      res.se+=max(now.fi,y[a]+y[au]+now.se);
    }
    return res;
  };
  auto ans=f(f,0,-1);
  ll ansx=max(ans.fi,ans.se);
  cout<<ansx;
}