#include <bits/stdc++.h>
using namespace std;
const int MAXN =  15 + 1e5;
long long s[MAXN];
int val[MAXN];
vector <int> g[MAXN];
void dfs(int node, int papa){
    s[node] = val[node];
    for(auto y : g[node]){
        if(y != papa){
            dfs(y, node);
            s[node] = max(s[node] + s[y], s[node]);
        }
    }
}
ifstream fin("lca.in");
ofstream fout("lca.out");
int main(){
    int n, indice;
    fin >> n;
    for(int i = 1; i <= n; ++i){
        int x;
        fin >> x;
        val[i] = x;
    }
    for(int i = 1; i < n; ++i){
        int x, y;
        fin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    dfs(1, 0);
    long long maxim = 0;
    for(int i = 1; i <= n; ++i){
        maxim = max(maxim, s[i]);
    }
    fout << maxim;
    return 0;
}