#include <bits/stdc++.h>

using namespace std;
ifstream fin("asmax.in");
ofstream fout("asmax.out");
const int NMAX = 16005;
int n,x,y;
bool vis[NMAX];
int dp[NMAX];
vector<int> G[NMAX];

void DFS(int q)
{
    vis[q]=1;
    for(auto x:G[q]) if(!vis[x])
    {
        DFS(x);
        dp[q]=max(dp[q],dp[q]+dp[x]);
    }
}

int main()
{
    fin>>n;
    for(int i=1;i<=n;i+=1) fin>>dp[i];
    for(int i=1;i<n;i+=1)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    DFS(1);
    int best=INT_MIN;
    for(int i=1;i<=n;i+=1) best=max(best,dp[i]);
    fout<<best;
    return 0;
}