use proconio::{input, marker::Usize1};

fn main() {
    input! {
        n: usize,
        a: [i64; n],
        b: [i64; n],
        edges: [(Usize1, Usize1); n - 1],
    }

    let mut graph = vec![vec![]; n];
    for &(u, v) in &edges {
        graph[u].push(v);
        graph[v].push(u);
    }

    let mut pre_order = vec![];
    let mut stack = vec![(0, !0)];
    while let Some((v, p)) = stack.pop() {
        pre_order.push(v);
        graph[v].retain(|&u| u != p);
        for &u in &graph[v] {
            stack.push((u, v));
        }
    }

    let mut dp = vec![[0; 2]; n];
    for &v in pre_order.iter().rev() {
        dp[v][0] = a[v];
        for &u in &graph[v] {
            dp[v][0] += dp[u][0].max(dp[u][1]);
            dp[v][1] += dp[u][0].max(dp[u][1] + b[v] + b[u]);
        }
    }

    let ans = dp[0][0].max(dp[0][1]);
    println!("{ans}");
}