#include <cmath>
#include <vector>
#include <iostream>
#include <algorithm>
#include <set>
#include <iomanip>
#include <numeric>
#include <queue>
#include <string>
#include <map>
#include <fstream>
#include <cassert>
#include <stack>


int main() {
	int n; std::cin >> n;
	std::vector<int> remove_score(n), rest_score(n);
	for (auto& a : remove_score) std::cin >> a;
	for (auto& b : rest_score) std::cin >> b;
	std::vector<std::vector<int>> nodes(n);
	for (auto i = 1; i < n; ++i) {
		int u, v; std::cin >> u >> v; --u; --v;
		nodes[u].push_back(v);
		nodes[v].push_back(u);
	}
	std::vector<int> parent(n, -1), node_count(n, 0);
	std::queue<int> queue; queue.push(0);
	while (!queue.empty()) {
		const auto front = queue.front(); queue.pop();
		node_count[front] = nodes[front].size();
		for (const auto to : nodes[front]) {
			if (node_count[to] == 0) {
				queue.push(to);
				parent[to] = front;
			}
		}
	}
	std::vector<long long int> remove(n), not_remove(n, 0);
	for (auto i = 0; i < n; ++i) {
		if (i > 0 && node_count[i] == 1) queue.push(i);
		remove[i] = remove_score[i];
	}
	while (!queue.empty()) {
		const auto front = queue.front(); queue.pop();
		for (const auto child : nodes[front]) if (parent[front] != child) {
			not_remove[front] += std::max(not_remove[child] + rest_score[front] + rest_score[child], remove[child]);
			remove[front] += std::max(not_remove[child], remove[child]);
		}
		if (parent[front] > 0 && --node_count[parent[front]] == 1) {
			queue.push(parent[front]);
		}
		if (parent[front] == 0 && --node_count[0] == 0) {
			queue.push(0);
		}
	}
	std::cout << std::max(remove[0], not_remove[0]) << '\n';
}