#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;

//template
#define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define ALL(v) (v).begin(),(v).end()
typedef long long int ll;
const int inf = 0x3fffffff; const ll INF = 0x1fffffffffffffff; const double eps=1e-12;
template<typename T>inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template<typename T>inline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
//end

vector<int> g[101010];
int a[101010],b[101010];
ll dp[101010][2]={};
void dfs(int v,int p){
   ll sum0=0,sum1=0;
   for(int t:g[v])if(t!=p){
      dfs(t,v);
      sum1+=max(dp[t][1]+b[t]+b[v],dp[t][0]);
      sum0+=max(dp[t][0],dp[t][1]);
   }
   dp[v][1]=sum1;
   dp[v][0]=sum0+a[v];
}

int main(){
   int n; cin>>n;
   rep(i,0,n)cin>>a[i];
   rep(i,0,n)cin>>b[i];
   rep(i,0,n-1){
      int u,v; cin>>u>>v;
      u--; v--;
      g[u].push_back(v);
      g[v].push_back(u);
   }
   dfs(0,-1);
   ll res=max(dp[0][0],dp[0][1]);
   cout<<res<<endl;
   return 0;
}