#include<bits/stdc++.h>
#define N 100020
using namespace std;
vector<int> lda[N];
int c[N], val[N], v[N], m=0;
void dfs(int nod){
	if(v[nod]) return;
	v[nod] = 1;
	int s=0;
	for(int i = 0;i<lda[nod].size();i++){
		s+=val[lda[nod][i]];
		dfs(lda[nod][i]);
	} 
	if(m<s+val[nod])m=s+val[nod];
}

int main(){
	int n, m1, x, y, i;
	freopen("asmax.in", "r", stdin);
	freopen("asmax.out", "w", stdout);
	//freopen("file.in", "r", stdin);
	//freopen("file.out", "w", stdout);
	scanf("%d", &n);
	for(i=1;i<=n;i++)scanf("%d", &val[i]);
	for(i=1;i<n;i++){
		scanf("%d%d", &x, &y);
		lda[x].push_back(y);
		lda[y].push_back(x);
	}
	v[1]=0;
	dfs(1);
	cout<<m;
	return 0;
}