#include<iostream>
#include<stdio.h>
#include<string.h>
#include<cmath>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
#include<queue>
#include<stack>
#include<sstream>
#include<iomanip>
#include<stdlib.h>
using namespace std;

int value1[100010];
vector<int> G[100010];
int choose[100010];
int notchoose[100010];
int used[100010];

void DFS(int point)
{
	used[point] = 1;
	int temp = 0;
	int temp1 = 0;
	choose[point] = value1[point];
	for (int i = 0; i < G[point].size(); i++)
	{
		if (used[G[point][i]] == 0)
		{
			DFS(G[point][i]);
			temp = 0;
			temp = max(choose[G[point][i]], temp);
			temp = max(notchoose[G[point][i]], temp);
			notchoose[point] += temp;
			choose[point] += notchoose[G[point][i]];
		}
	}
}

int main()
{
	freopen("profitz.in","r",stdin);
	freopen("profitz.out","w",stdout);
	int n;
	scanf("%d", &n);
	for (int i = 0; i < n; i++)
	{
		scanf("%d", value1 + i);
	}
	for (int i = 0; i < n - 1; i++)
	{
		int point1, point2;
		scanf("%d%d", &point1, &point2);
		point1--;
		point2--;
		G[point1].push_back(point2);
		G[point2].push_back(point1);
	}
	DFS(0);
	int ans = 0;
	ans = max(choose[0], ans);
	ans = max(notchoose[0], ans);
	printf("%d\n", ans);
	return 0;
}