const INF: isize = 1isize << 60;

fn dfs(cur: usize, prev: usize, paths: &Vec<Vec<usize>>, a: &Vec<isize>, b: &Vec<isize>, dp: &mut Vec<Vec<isize>>) {
    let mut score = 0isize;
    let mut del_score = 0isize;
    for &v in paths[cur].iter() {
        if prev == v { continue; }
        dfs(v, cur, paths, a, b, dp);
        let used_score = b[v] + b[cur] + dp[v][1];
        let unused_score = dp[v][0];
        score += used_score.max(unused_score);
        del_score += dp[v][0].max(dp[v][1]);
    }
    dp[cur][0] = a[cur] + del_score;
    dp[cur][1] = score;
}

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut a = String::new();
    std::io::stdin().read_line(&mut a).ok();
    let a: Vec<isize> = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let mut b = String::new();
    std::io::stdin().read_line(&mut b).ok();
    let b: Vec<isize> = b.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let mut paths = vec![vec![]; n];
    for _ in 0..n-1 {
        let mut ab = String::new();
        std::io::stdin().read_line(&mut ab).ok();
        let ab: Vec<usize> = ab.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
        let a = ab[0]-1;
        let b = ab[1]-1;
        paths[a].push(b);
        paths[b].push(a);
    }

    let mut dp = vec![vec![-INF; 2]; n];
    dfs(0, 0, &paths, &a, &b, &mut dp);
    println!("{}", dp[0][0].max(dp[0][1]));
}