#include <bits/stdc++.h>
// #include <atcoder/dsu>
// #include<atcoder/modint>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define YES cout<< "Yes"<< endl
#define NO cout<< "No"<< endl
#define Rep(i,s,n) for(int i = (int)(s); i < (int)(n); i++)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
template<class T, class U> bool chmax(T& x, const U& y){
    if (x < y) { x = y; return true; }
    return false;
}
template<class T, class U> bool chmin(T& x, const U& y){
    if (y < x) { x = y; return true; }
    return false;
}
#define UNIQUE(a) a.erase(unique(a.begin(),a.end()),a.end())
using namespace std;
// using mint = atcoder::modint998244353;
// using mint2 = atcoder::modint1000000007;
// using namespace atcoder;
using ll = long long;
using V = vector<ll>;
using P = pair<ll,ll>;
using i128 = __int128;

void solve(){
    int n; cin >> n;
    vector<ll> s(n);
    rep(i,n) cin >> s[i];
    vector<vector<int>> g(n);
    vector<bool> seen(n);
    rep(i,n-1){
        int a,b; cin >> a >> b; a--; b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    ll ans = -1;
    auto f = [&](auto f,int v,int pv,ll sum) -> void{
        //cout << v << " " << pv << " " << sum << endl;
        seen[v] = true;
        chmax(ans,sum);
        for(auto nv : g[v]){
            if(nv == pv) continue;
            if(s[nv] > s[v]){
                f(f,nv,v,sum+s[nv]);
            }
        }
    };
    rep(i,n){
        if(!seen[i]) f(f,i,-1,s[i]);
    }
    cout << ans << endl;
}
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int t; 
    t = 1;
    //cin >> t;
    rep(i,t) solve();
}