#include <iostream>
#include <fstream>
#include <vector>
#define MAX 16002
using namespace std;
int n,x,y,s[MAX],c[MAX],ans=-1000;
vector<int> v[MAX];

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

void dfs(int nod, int tata){
    s[nod] = c[nod];
    for(auto fiu: v[nod]){
        if(fiu == tata){
            continue;
        }
        dfs(fiu, nod);
        s[nod] = max(s[nod], s[nod]+s[fiu]);
    }
    ans = max(ans, s[nod]);
}

int main()
{
    fin >> n;
    for(int i = 1; i <= n; i++){
        fin >> c[i];
    }
    for(int i = 1; i < n; i++){
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1, -1);
    fout << ans;
    return 0;
}