#include <bits/stdc++.h>
#define rep(a,n) for (int a = 0; a < (n); ++a)
using namespace std;
using ll = long long;
typedef pair<int,int> P;
typedef pair<ll,P> PP;
typedef vector<vector<int> > Graph;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const ll INF = 1e18;


ll dp[100010][2];
Graph g;
vector<ll>a,b;

void dfs(int v,int p=-1){
    ll res1 = 0;
    ll res0 = 0;
    for(int i=0;i<g[v].size();i++){
        int x = g[v][i];
        if(x==p)continue;
        dfs(x,v);
        res1 += max(dp[x][0],dp[x][1]+b[x]+b[v]);
        res0 += max(dp[x][0],dp[x][1]);
    }
    res0 += a[v];
    dp[v][0]=res0;
    dp[v][1]=res1;
    return;
}

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

    return 0;
}