#include<fstream>
#include<vector>
std::ifstream cin("asmax.in");
std::ofstream cout("asmax.out");
using namespace std;
int n, ans = -0x3F3F3F3F, u, v;
vector<int>g[16001], price;
void dfs(int node = 1, int parent = 0) {
	for (auto i : g[node]) {
		if (i ^ parent) {
			dfs(i, node);
			price[node] = max(price[node], price[node] + price[i]);
		}
	}
}
int main() {
	cin >> n;
	price = vector<int>(n + 1);
	for (int i = 1; i <= n; ++i) cin >> price[i];
	for (int i = 1; i < n; ++i) {
		cin >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	dfs();
	for (int i = 1; i <= n; i++)
		ans = max(ans, price[i]);
	cout << ans;
	return 0;
}