#include <bits/stdc++.h>

using namespace std;

const int MAXN = 16005;

int v[MAXN], dp[MAXN];
vector<int> graf[MAXN];

void dfs(int nod, int prec){
    for(auto x:graf[nod]){
        if(x == prec) continue;
        dfs(x, nod);
        dp[nod] = max(dp[nod], dp[nod] + dp[x]);
    }
}

int main()
{
    ifstream fin("asmax.in");
    ofstream fout("asmax.out");
    int n;
    fin >> n;
    for(int i = 1; i <= n; ++i)
        fin >> v[i];
    for(int i = 1; i < n; ++i){
        int x, y;
        fin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(int i = 1; i <= n; ++i) dp[i] = v[i];
    dfs(1, 0);
    int ans = -1e9;
    for(int i = 1; i <= n; ++i)
        ans = max(ans, dp[i]);
    fout << ans;
    return 0;
}