#include "bits/stdc++.h"
using namespace std;
#define ll long long

int N;
int a[100010], b[100010];
ll dp[100010][2];

void dfs(const vector<vector<int>> &G, int v, int p = -1) {
	ll sum0 = a[v], sum1 = 0;
	for (auto nv : G[v]) {
		if (nv == p)continue;
		dfs(G, nv, v);
		sum0 += max(dp[nv][0], dp[nv][1]);
		sum1 += max(dp[nv][0], dp[nv][1] + b[v] + b[nv]);
	}
	dp[v][0] = sum0, dp[v][1] = sum1;
}

signed main() {
	cin >> N;
	for (int i = 0; i < N; i++)cin >> a[i];
	for (int i = 0; i < N; i++)cin >> b[i];
	vector<vector<int>>G(N);
	for (int i = 0; i < N - 1; i++) {
		int u, v; cin >> u >> v; u--; v--;
		G[u].push_back(v);
		G[v].push_back(u);
	}
	dfs(G, 0);
	cout << max(dp[0][0], dp[0][1]) << endl;
	return 0;
}