/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.09.05 03:09:52
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int n;
vector<vector<int>> g;
vector<ll> a,b;

pair<ll,ll> dfs(int v, int p = -1) {
    pair<ll,ll> ret = {a[v],0};
    for(int u : g[v]) {
        if (u == p) continue;
        auto t = dfs(u,v);
        ret.first += max(t.first,t.second);
        ret.second += max(b[u] + t.second + b[v], t.first);
    }
    return ret;
}
int main() {
    cin >> n;
    a.resize(n);
    b.resize(n);
    g.resize(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    for (int i = 0; i < n; i++) {
        cin >> b[i];
    }
    for (int i = 0; i < n-1; i++) {
        int u,v;cin >> u >> v;
        u--;v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    auto ans = dfs(0);
    cout << max(ans.first,ans.second) << endl;
    return 0;
}