#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>
#include <cctype>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <utility>


using namespace std;
typedef long long ll;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T> T gcd(T a, T b) { a = abs(a), b = abs(b); while (b > 0) { tie(a, b) = make_pair(b, a % b); } return a; }
//mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

constexpr long long INF = 1LL << 60;
constexpr int inf = 1000000007;
constexpr long long mod = 1000000007LL;
//constexpr long long mod = 998244353LL;


int main()
{

	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	int n; cin >> n;
	vector<ll> a(n); for (int i = 0; i < n; i++) cin >> a[i];
	vector<ll> b(n); for (int i = 0; i < n; i++) cin >> b[i];
	vector<vector<int>> g(n);
	for (int i = 1; i < n; i++) {
		int u, v; cin >> u >> v;
		u--; v--;
		g[u].emplace_back(v);
		g[v].emplace_back(u);
	}

	vector<vector<ll>> dp(n, vector<ll>(2));

	auto dfs = [&](auto&& f, int cur, int pre)->void {
		for (auto nxt : g[cur]) {
			if (nxt == pre) continue;
			f(f, nxt, cur);
		}
		dp[cur][1] += a[cur];
		for (auto nxt : g[cur]) {
			if (nxt == pre) continue;
			dp[cur][0] += max(dp[nxt][0] + b[nxt] + b[cur], dp[nxt][1]);
			dp[cur][1] += max(dp[nxt][0], dp[nxt][1]);
		}
	};
	dfs(dfs, 0, -1);
	cout << max(dp[0][0], dp[0][1]) << endl;
	return 0;
}