#include <algorithm>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <vector>
#include <list>
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
//#define cerr if(false) cerr
#ifdef DEBUG
#define show(...) cerr << #__VA_ARGS__ << " = ", debug(__VA_ARGS__);
#else
#define show(...) 42
#endif
using namespace std;
using ll = long long;
using pii = pair<int, int>;
template <typename T, typename S>
ostream& operator<<(ostream& os, pair<T, S> a) {
    os << '(' << a.first << ',' << a.second << ')';
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, vector<T> v) {
    for (auto x : v) os << x << ' ';
    return os;
}
void debug() {
    cerr << '\n';
}
template <typename H, typename... T>
void debug(H a, T... b) {
    cerr << a;
    if (sizeof...(b)) cerr << ", ";
    debug(b...);
}
ll dp[2][100005];
vector<int>g[100005];
ll a[100005];
ll b[100005];
void dfs(int s, int p){
    for(int x: g[s]){
        if(x == p)continue;
        dfs(x, s);
        dp[0][s] += max(dp[0][x], dp[1][x]);
        dp[1][s] += max(dp[0][x], dp[1][x] + b[s] + b[x]);
    }
    dp[0][s] += a[s];
}
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n;
    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--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(0, -1);
    cout << max(dp[0][0], dp[1][0]) << endl;
}