#include <bits/stdc++.h>

using namespace std;
ifstream in("asmax.in");
ofstream out("asmax.out");
const int N = 16005;
int val[N],dp[N];
bool viz[N];
vector<int> v[N];

void dfs(int i)
{
    viz[i] = 1;
    dp[i] = val[i];
    for (auto it: v[i])
        if (!viz[it])
        {
            dfs(it);
            dp[i] = max(dp[i],dp[i]+dp[it]);
        }
}

int main()
{
    int n;
    in >> n;
    for (int i = 1; i<=n; i++)
        in >> val[i];
    for (int i = 1; i<n; i++)
    {
        int x,y;
        in >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1);
    int Max = -N;
    for (int i = 1; i<=n; i++)
        Max = max(Max,dp[i]);
    out << Max;
}