#include <bits/stdc++.h>
 
using namespace std;
 
inline void Open(const string Name) {
    #ifndef ONLINE_JUDGE
        (void)!freopen((Name + ".in").c_str(), "r", stdin);
        (void)!freopen((Name + ".out").c_str(), "w", stdout);
    #endif
}
 
vector <int> Gr[16001];
 
bitset <16001> vis;
 
int val[16001], dp[16001];
int N, ans = INT_MIN, nod, root;
 
void dfs(int v, int dad = -1) {
    vis[v] = 1, dp[v] = val[v];
    for(int to : Gr[v]) {
        if(to == dad)
            continue;
        dfs(to, v);
        dp[v] = max(dp[v], dp[v] + dp[to]);
    }
}
 
void solve() {
    cin >> N;
    for(int i = 1;i <= N;i++)
        cin >> val[i];
 
    for(int i = 1, a, b;i < N;i++) {
        cin >> a >> b;
        Gr[a].emplace_back(b);
        Gr[b].emplace_back(a);
    }

    dfs(1);
 
    for(int i = 1;i <= N;i++)
        ans = max(ans, dp[i]);
    cout << ans;
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
 
    Open("asmax");
 
    int T = 1;
    for(;T;T--) {
        solve();
    }
 
    return 0;
}