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

using namespace std;

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

#define lim 16010
#define inf 2e9
int n,ini[lim];
vector <int> G[lim];
int dp[lim];
bool viz[lim];

void dfs(int x)
{
    viz[x]=1;
    dp[x]=ini[x];
    for (auto it:G[x])
        if (!viz[it])
        {
            dfs(it);
            dp[x] +=  max (0,dp[it]);
        }
}

int main()
{
    int x,y;
    fin>>n;
    for (int i=1; i<=n; i++)    fin>>ini[i];
    for (int i=1; i<=n; i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    dfs(1);

    int rez=-inf;
    for (int i=1; i<=n; i++)
        rez = max(rez,dp[i]);
    fout<<rez;

    fin.close();
    fout.close();
    return 0;
}