#include<iostream>
#include<cstdio>
#include<vector>
#include<cstring>

#define pb push_back

using namespace std;

const int maxn = 100000 + 100;
const int maxm = 50 + 5;

int n;
int A[maxn];

vector<int >C[maxn];

bool vis[maxn][maxm];

int a;
int b;

int f[maxn][2];

int cnt1;
int cnt2;

inline void find(int u)
{
	cnt1 = 0;
	cnt2 = 0;
	f[u][1] = A[u]; 
	for(int i=0;i<C[u].size();++i)
	{
		if(!vis[u][i])
		{
			vis[u][i] = true;
			int t = C[u][i];
			for(int j=0;j<C[t].size();++j)
			{
				if(C[t][j]==u)
				{
					vis[t][j] = true;
					break;
				}
			}
			find(t);
			f[u][0]+=max(f[t][1],f[t][0]);
			f[u][1]+=f[t][0];
		}
	}
}

int main()
{
	freopen("profitz.in","r",stdin);
	freopen("profitz.out","w",stdout);
	memset(vis,false,sizeof(vis));
	memset(f,0,sizeof(f));
	scanf("%d",&n);
	for(int i=1;i<=n;++i)
	{
		scanf("%d",&A[i]);
	}
	for(int i=1;i<=n-1;++i)
	{
		scanf("%d%d",&a,&b);
		C[a].pb(b);
		C[b].pb(a);
	}
	find(1);
	cout<<max(f[1][0],f[1][1]);
	return 0;
}