#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
constexpr int INF = 1e9;
constexpr long long LINF = 1e17;
constexpr int MOD = 1000000007;
constexpr double PI = 3.14159265358979323846;
int n;
vector<int> tree[100005];
ll a[100005];
ll b[100005];
ll dp[100005][2];

pll dfs(int i,int before){
    ll one = a[i];
    ll two = 0;
    for(int j:tree[i]){
        if(j==before) continue;
        pll now = dfs(j,i);
        one += max(now.first,now.second);
        two += max(now.first,now.second+b[j]+b[i]);
    }
    dp[i][0] = one;
    dp[i][1] = two;
    return pll(one,two);
}

int main(){
    cin >> n;
    rep(i,n) cin >> a[i];
    rep(i,n) cin >> b[i];
    rep(i,n-1){
        int u,v;
        cin >> u >> v;
        --u;--v;
        tree[u].push_back(v);
        tree[v].push_back(u);
    }
    dfs(0,-1);
    cout << max(dp[0][0],dp[0][1]) << endl;
    return 0;
}