#include <bits/stdc++.h>
#define NMAX 16001
using namespace std;

ifstream fin("asmax.in");
ofstream fout("asmax.out");

int n;
int val[NMAX];
bitset<NMAX> vis;
vector<int> graf[NMAX];
int dp[NMAX];

int dfs(int i)
{
    vis[i]=1;
    dp[i] = val[i];
    for(auto q:graf[i])
        if(!vis[q])
            dp[i]=max(dp[i], dp[i]+dfs(q));
    return dp[i];
}

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