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

ifstream fin("asmax.in");
ofstream fout("asmax.out");

const int MAX = 16005;
const int INF = 0x3f3f3f3f;
using VI = vector<int>;
vector<VI> G;
vector<bool> s;
int N;
VI val;
int smax = -INF;
VI sum;

void Read();
void DF( int x );

int main()
{
	Read();
	DF(1);
	
	fout << smax << '\n';
	
	fin.close();
	fout.close();
	return 0;
}

void Read()
{
	int i, x, y;
	
	fin >> N;
	G = vector<VI>(N + 1);
	s = vector<bool>(N + 1);
	val = vector<int>(N + 1);
	sum = vector<int>(N + 1);
	for ( i = 1; i <= N; i++ )
	{
		fin >> x;
		val[i] = x;
	}
	
	for ( i = 1; i < N; i++ )
	{
		fin >> x >> y;
		G[x].push_back(y);
		G[y].push_back(x);
	}
}

void DF( int x )
{
	s[x] = true;
	
	//cout << x << ' ';
	
	sum[x] = val[x];
	for ( const auto& a : G[x] )
	{
		if ( s[a] ) continue;
		
		DF(a);
		if ( sum[a] > 0 )
			sum[x] += sum[a];
	}
	
	smax = max( smax, sum[x] );
	
	//cout << x << ' ' << sum[x]; cin.get();
}