#include <iostream>
#include<string>
#include<vector>
#include<fstream>
#include<list>
using namespace std;


void dfs_asmax(int nr_noduri, vector<int>&v, vector<vector<int>>&lista, vector<bool>& vizit, int& nod) {

	vizit[nod] = 1;

	for (int i = 0; i < lista[nod].size(); i++) {

		if (vizit[lista[nod][i]] == false) {

			dfs_asmax(nr_noduri, v, lista, vizit, lista[nod][i]);

			if (v[lista[nod][i]] > 0) {

				v[nod] += v[lista[nod][i]];
			}
		}
	}
}
void asmax() {

	fstream f("asmax.in");
	int n;//nr noduri
	f >> n;

	vector<int>v(n + 1, 0);//valorile nodurilor
	for (int i = 1; i <= n; i++) {

		f >> v[i];
	}

	int x, y;
	vector<vector<int>>lista;//lista de muchii
	lista.resize(n + 1);
	while (f >> x >> y) {

		lista[x].push_back(y);
		lista[y].push_back(x);
	}

	f.close();

	vector<bool> vizit(n + 1, 0);//vector de vizite

	int maxi = -1001;//suma noului subarbore

	dfs_asmax(n, v, lista, vizit, n);


	for (int i = 1; i <= n; i++) {

		if (v[i] > maxi) {

			maxi = v[i];
		}
	}

	ofstream g("asmax.out");
	g << maxi;
	g.close();
}


int main()
{
	asmax();
}