#include <bits/stdc++.h>

using namespace std;

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

vector <int> g[16001];

int n;

int fre[16001];
int a[16001], cnt = 0, dp[160001], ans;
void dfs(int k)
{
    fre[k] = 1;
    for(auto x:g[k])
    {
        if(!fre[x])
        {
            dfs(x);
            if(dp[x] > 0)
            dp[k] += dp[x];
        }
    }
    ans = max(dp[k], ans);
}

int main()
{
    in >> n;
    for(int i = 1; i <= n; i++)
        in >> dp[i];
    int l, c;
    while(in >> l >> c)
    {
        g[l].push_back(c);
        g[c].push_back(l);
    }
    ans = dp[1];
    dfs(1);
    out << ans;
    return 0;
}