#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define modulo 1000000007
#define mod(mod_x) ((((long long)mod_x+modulo))%modulo)
#define Inf 1000000000000000000	

int N;
vector<vector<int>> E;
vector<long long> a,b;

vector<vector<long long>> dp;

void dfs(int now,int p){
	dp[now][0] = a[now];
	dp[now][1] = 0LL;
	for(int i=0;i<E[now].size();i++){
		int to = E[now][i];
		if(to==p)continue;
		dfs(to,now);
		dp[now][0] += max(dp[to][0],dp[to][1]);
		dp[now][1] += max(dp[to][0],dp[to][1] + b[to] + b[now]);
	}
	
}

int main(){

	cin>>N;
	E.resize(N,vector<int>());
	a.resize(N);
	b.resize(N);
	
	rep(i,N)scanf("%lld",&a[i]);
	rep(i,N)scanf("%lld",&b[i]);
	rep(i,N-1){
		int x,y;
		scanf("%d %d",&x,&y);
		x--;y--;
		E[x].push_back(y);
		E[y].push_back(x);
	}
	
	dp.resize(N,vector<long long>(2,0LL));
	
	dfs(0,-1);
	//rep(i,N)cout<<dp[i][0]<<','<<dp[i][1]<<endl;
	cout<<max(dp[0][0],dp[0][1])<<endl;
	
	return 0;
}