#include<cstdio>
#include<vector>
#define lim 16001
using namespace std;
int V[lim],n,x,y,maxu,viz[lim],suma[lim],i;
vector<int>G[lim];
void dfs(int nod){
	viz[nod]=1;
	int v;
	
	for(int i=0;i<G[nod].size();++i){
		v=G[nod][i];
		if(!viz[v] ){
			dfs(v);
			if(V[v]>0)
				V[nod]+=V[v];
		}
	}
}
int main (){
	freopen("asmax.in","r",stdin);
	freopen("asmax.out","w",stdout);
	scanf("%d",&n);
	maxu=-1000000;
	for(i=1;i<=n;i++)
		scanf("%d",&V[i]);
	for(i=1;i<=n;i++){
		scanf("%d%d",&x,&y);
		G[x].push_back(y);
		G[y].push_back(x);
	}
	dfs(1);
	for(i=1;i<=n;i++)
		if(maxu<V[i])
			maxu=V[i];
	printf("%d",maxu);
	return 0;
	
}