#include<bits/stdc++.h>
using namespace std;
const int maxn = 10000;

int head[maxn],to[maxn],nt[maxn],cnt = 0;
int happy[maxn],f[maxn][2],l[maxn];
int n,root=1;

void add(int x,int y){
	cnt++;
	to[cnt] = y;
	nt[cnt] = head[x];
	head[x] = cnt;
}

void dfs(int u,int fa){
	f[u][0] = 0;
	f[u][1] = happy[u];
	for(int i = head[u];i;i=nt[i]){
		int v = to[i];
		if(v == fa) continue;
		dfs(v,u);
		f[u][0] += max(f[v][0],f[v][1]);
		f[u][1] += f[v][0];
	}
}

int main(){
	freopen("P135_2.in","r",stdin); 
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&happy[i]);
	int x,y,m1 = 0,m2 = -1;
	for(int i=1;i<=n-1;i++){
		scanf("%d %d",&x,&y);
		if(x != y) l[x]++;
		add(x,y);
		add(y,x);
	}
	while(l[root] != 0) root++;
	
	dfs(root,0);
	
	printf("%d",max(f[root][0],f[root][1]));
	return 0;
}