#include <fstream>
#include <algorithm>
#include <vector>
#define N 30010
using namespace std;
typedef long long ll;
ifstream in("makeup.in");
ofstream out("makeup.out");
int n;
ll w[N]={0};
vector<int> G[N];
bool l[N]={0};
ll ans=0;
ll f[N]={0};
void DFS(int u)
{
	int i,v;
	l[u]=1;
	f[u]=w[u];
	for(i=0;i<G[u].size();i++)
	{
		v=G[u][i];
		if(!l[v])
		{
			l[v]=1;
			DFS(v);
			if(f[v]>0)f[u]+=f[v];
		}
	}
}
void read()
{
	int i,u,v;
	in>>n;
	for(i=1;i<=n;i++)in>>w[i];
	for(i=1;i<=n;i++)
	{
		in>>u>>v;
		G[u].push_back(v);
		G[v].push_back(u);
	}
}
void work()
{
	int i;
	DFS(1);
	for(i=1;i<=n;i++)ans=max(ans,f[i]);
	out<<ans<<endl;
}
int main()
{
	read();
	work();
	return 0;
}