#include "bits/stdc++.h"
using namespace std;
#define int long long
#define REP(i, n) for (int i = 0; i < (int)n; ++i)
#define RREP(i, n) for (int i = (int)n - 1; i >= 0; --i)
#define FOR(i, s, n) for (int i = s; i < (int)n; ++i)
#define RFOR(i, s, n) for (int i = (int)n - 1; i >= s; --i)
#define ALL(a) a.begin(), a.end()
#define IN(a, x, b) (a <= x && x < b)
template<class T>istream&operator >>(istream&is,vector<T>&vec){for(T&x:vec)is>>x;return is;}
template<class T>inline void out(T t){cout << t << "\n";}
template<class T,class... Ts>inline void out(T t,Ts... ts){cout << t << " ";out(ts...);}
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;}
constexpr int INF = 1e18;



signed main(){
	int N;
	cin >> N;
	vector<int>a(N), b(N);
	cin >> a >> b;
	vector<vector<int>>g(N);
	REP(i, N - 1) {
		int a, b;
		cin >> a >> b;
		--a; --b;
		g[a].emplace_back(b);
		g[b].emplace_back(a);
	}
	vector<vector<int>>dp(N, vector<int>(2, -INF));
	auto dfs = [&](auto&&f, int now, int par) -> void {
		int child = 0;
		for(auto e: g[now]) {
			if(e == par) continue;
			++child;
		}
		if(child == 0) {
			dp[now][0] = a[now];
			dp[now][1] = 0;
			return;
		}
		dp[now][0] = a[now];
		dp[now][1] = 0;
		for(auto e: g[now]) {
			if(e == par) continue;
			f(f, e, now);
			dp[now][1] += max(dp[e][0], dp[e][1] + b[e] + b[now]);
			dp[now][0] += max(dp[e][0], dp[e][1]);
		}
	};
	dfs(dfs, 0, -1);
	out(max(dp[0][0], dp[0][1]));
}