#![allow(unused_imports)]

fn main() {
    input! {
        n: usize,
        s: [u64; n],
        e: [(Usize1, Usize1); n-1],
    }
    let mut g = vec![vec![]; n];
    let mut d = vec![0; n];
    for (a, b) in e {
        if s[a] < s[b] {
            g[a].push(b);
            d[b] += 1;
        }
        if s[b] < s[a] {
            g[b].push(a);
            d[a] += 1;
        }
    }
    let mut dp = vec![0; n];
    let mut que = VecDeque::new();
    for (i, &d) in d.iter().enumerate() {
        if d == 0 {
            que.push_back(i);
        }
    }
    // eprintln!("{que:?}");
    while let Some(v) = que.pop_front() {
        dp[v] += s[v];
        for &u in &g[v] {
            chmax!(dp[u], dp[v]);
            d[u] -= 1;
            if d[u] == 0 {
                que.push_back(u);
            }
        }
    }
    println!("{}", dp.iter().max().unwrap());
}

use proconio::{input, marker::*};
use itertools::{iproduct, izip, Itertools as _};
use std::{cmp::Reverse, collections::*};

#[macro_export]
macro_rules! chmax {
    ($a:expr, $b:expr) => {{
        let tmp = $b;
        if $a < tmp {
            $a = tmp;
            true
        } else {
            false
        }
    }};
}

#[macro_export]
macro_rules! chmin {
    ($a:expr, $b:expr) => {{
        let tmp = $b;
        if $a > tmp {
            $a = tmp;
            true
        } else {
            false
        }
    }};
}

#[macro_export]
/// mvec![]
macro_rules! mvec {
    ($val:expr; ()) => {
        $val
    };
    ($val:expr; ($size:expr $(,$rest:expr)*)) => {
        vec![mvec![$val; ($($rest),*)]; $size]
    };
}