#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int MAX = 100010;

vector<ll> dp0(MAX, 0), dp1(MAX, 0), a(MAX), b(MAX);
vector<vector<int>> adj(MAX);

void dfs(int i, int p) {
	dp0[i] += a[i];
	for (int j : adj[i]) {
		if (j == p) continue;
		dfs(j, i);
		dp0[i] += max(dp0[j], dp1[j]);
		dp1[i] += max(dp0[j], dp1[j] + b[i] + b[j]);
	}
	return;
}

int main() {
	int n; cin >> n;
	for (int i = 0; i < n; ++i) cin >> a[i];
	for (int i = 0; i < n; ++i) cin >> b[i];
	for (int i = 0; i < n-1; ++i) {
		int u, v; cin >> u >> v; u--; v--;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	dfs(0, -1);
	cout << max(dp0[0], dp1[0]) << endl;
	return 0;
}