use std::cmp::*;

macro_rules !input {(source =$s :expr ,$($r :tt ) *) =>{let mut iter =$s .split_whitespace () ;let mut next =||{iter .next () .unwrap () } ;input_inner !{next ,$($r ) *} } ;($($r :tt ) *) =>{let stdin =std ::io ::stdin () ;let mut bytes =std ::io ::Read ::bytes (std ::io ::BufReader ::new (stdin .lock () ) ) ;let mut next =move ||->String {bytes .by_ref () .map (|r |r .unwrap () as char ) .skip_while (|c |c .is_whitespace () ) .take_while (|c |!c .is_whitespace () ) .collect () } ;input_inner !{next ,$($r ) *} } ;}
macro_rules !input_inner {($next :expr ) =>{} ;($next :expr ,) =>{} ;($next :expr ,$var :ident :$t :tt $($r :tt ) *) =>{let $var =read_value !($next ,$t ) ;input_inner !{$next $($r ) *} } ;}
macro_rules !read_value {($next :expr ,($($t :tt ) ,*) ) =>{($(read_value !($next ,$t ) ) ,*) } ;($next :expr ,[$t :tt ;$len :expr ] ) =>{(0 ..$len ) .map (|_ |read_value !($next ,$t ) ) .collect ::<Vec <_ >>() } ;($next :expr ,chars ) =>{read_value !($next ,String ) .chars () .collect ::<Vec <char >>() } ;($next :expr ,usize1 ) =>{read_value !($next ,usize ) -1 } ;($next :expr ,$t :ty ) =>{$next () .parse ::<$t >() .expect ("Parse error" ) } ;}

fn main() {
    input! {
        n: usize,
        a: [i64; n],
        b: [i64; n],
        uv: [(usize, usize); n-1]
    }
    let mut to = vec![vec![]; n];
    for &(u, v) in uv.iter() {
        to[u - 1].push(v - 1);
        to[v - 1].push(u - 1);
    }
    let mut dp = vec![vec![0; 2]; n];
    dfs(0, 0, &to, &a, &b, &mut dp);
    let ans = max(dp[0][0], dp[0][1]);
    println!("{}", ans);
}

fn dfs(
    u: usize,
    p: usize,
    to: &Vec<Vec<usize>>,
    a: &Vec<i64>,
    b: &Vec<i64>,
    dp: &mut Vec<Vec<i64>>,
) {
    dp[u][0] = a[u];
    for &v in to[u].iter() {
        if v == p {
            continue;
        }
        dfs(v, u, to, a, b, dp);
        dp[u][0] += max(dp[v][0], dp[v][1]);
        dp[u][1] += max(dp[v][0], dp[v][1] + b[u] + b[v]);
    }
}