#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

bool viz[16001];
int n, v[16001], sum=-1001, scor[16001];

vector <int> a[16001];

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

void dfs(int x)
{
    viz[x]=true;
    scor[x]=v[x];
    for(auto y:a[x]){
        if(!viz[y]){
            dfs(y);
            if(scor[y]>0)
                scor[x]+=scor[y];
        }
    }
    sum=max(sum,scor[x]);
}

int main()
{
    in>>n;
    for(int i=1;i<=n;i++)
        in>>v[i];
    int x,y;
    while(in>>x>>y){
        a[x].push_back(y);
        a[y].push_back(x);
    }
    dfs(1);
    out<<sum;
    return 0;
}