#include <bits/stdc++.h>
#define rep(i, a) for (int i = (int)0; i < (int)a; ++i)
#define rrep(i, a) for (int i = (int)a - 1; i >= 0; --i)
#define REP(i, a, b) for (int i = (int)a; i < (int)b; ++i)
#define RREP(i, a, b) for (int i = (int)a - 1; i >= b; --i)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define popcount __builtin_popcount
using ll = long long;
constexpr ll mod = 1e9 + 7;
constexpr ll INF = 1LL << 60;


template <class T>
inline bool chmin(T &a, T b)
{
	if (a > b)
	{
		a = b;
		return true;
	}
	return false;
}
template <class T>
inline bool chmax(T &a, T b)
{
	if (a < b)
	{
		a = b;
		return true;
	}
	return false;
}

ll gcd(ll n, ll m)
{
	ll tmp;
	while (m != 0)
	{
		tmp = n % m;
		n = m;
		m = tmp;
	}
	return n;
}

ll lcm(ll n, ll m)
{
	return abs(n) / gcd(n, m) * abs(m); //gl=xy
}

using namespace std;

void solve(){
	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].eb(v);
		g[v].eb(u);
	}
	vector<vector<ll>>dp(n+1,vector<ll>(2,-1));
	auto dfs=[&](auto self,int v,int c,int par=-1)-> ll{
		if(~dp[v][c])return dp[v][c];

		ll res=0;
		for(auto x:g[v]){
			if(x!=par){
				if(c==1)res+=max(self(self,x,0,v),self(self,x,1,v)+b[v]+b[x]);
				else res+=max(self(self,x,0,v),self(self,x,1,v));
			}
		}
		if(c==0)return dp[v][c]=res+a[v];
		else return dp[v][c]=res;
	};
	cout<<max(dfs(dfs,0,0),dfs(dfs,0,1))<<"\n";
	//rep(i,n)rep(j,2)cout<<dp[i][j]<<"\n";
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}