#include <bits/stdc++.h>

const int N = 100010;
using ll = long long;

int a[N], b[N];
std::vector<int> e[N];
ll dp[N][2];

void dfs(int u, int fa){
    dp[u][0] = a[u];
    for (auto v : e[u]){
        if (v == fa){
            continue;
        }
        dfs(v, u);
        dp[u][0] += std::max(dp[v][0], dp[v][1]);
        dp[u][1] += std::max(dp[v][0], dp[v][1] + b[u] + b[v]);
    }
}

int main(){
    int n;
    scanf("%d", &n);
    for (int i = 1; i <= n; ++ i){
        scanf("%d", &a[i]);
    }
    for (int i = 1; i <= n; ++ i){
        scanf("%d", &b[i]);
    }
    for (int i = 0, u, v; i < n - 1; ++ i){
        scanf("%d%d", &u, &v);
        e[u].emplace_back(v);
        e[v].emplace_back(u);
    }
    dfs(1, 0);
    printf("%lld\n", std::max(dp[1][0], dp[1][1]));
    return 0;
}