#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
inline int read()
{
	int x=0,f=1;
	char ch=getchar();
	while(ch<'0'||ch>'9')
	{
		if(ch=='-')  f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9')
	{
		x=(x<<3)+(x<<1)+ch-'0';
		ch=getchar();
	}
	return x*f;
}
int n,x,y,jishu;
int head[100010],a[100010];
long long f[100010][2],ans;
struct bian
{
	int qi,zhong,next;
};
bian c[200010];
void add(int x,int y)
{
	c[++jishu].qi=x;
	c[jishu].zhong=y;
	c[jishu].next=head[x];
	head[x]=jishu;
}
void dfs(int x,int fa)
{
	f[x][1]=a[x];
	for(int i=head[x];i;i=c[i].next)
	{
		int e=c[i].zhong;
		if(e!=fa)
		{
			dfs(e,x);
			f[x][0]+=max(f[e][0],f[e][1]);
			f[x][1]+=f[e][0];
		}
	}
}
int main()
{
	freopen("profitz.in","r",stdin);
	freopen("profitz.out","w",stdout);
	n=read();
	for(int i=1;i<=n;++i)  a[i]=read();
	for(int i=1;i<n;++i)
	{
		x=read();y=read();
		add(x,y);
		add(y,x);
	}
	dfs(1,-1);
	ans=max(f[1][0],f[1][1]);
	cout<<ans;
	return 0;
}