/* #region Head */

// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pll = pair<ll, ll>;
template <class T> using vc = vector<T>;
template <class T> using vvc = vc<vc<T>>;
using vll = vc<ll>;
using vvll = vvc<ll>;
using vld = vc<ld>;
using vvld = vvc<ld>;
using vs = vc<string>;
using vvs = vvc<string>;
template <class T, class U> using um = unordered_map<T, U>;
template <class T> using pq = priority_queue<T>;
template <class T> using pqa = priority_queue<T, vc<T>, greater<T>>;
template <class T> using us = unordered_set<T>;

#define REP(i, m, n) for (ll i = (m), i##_len = (ll)(n); i < i##_len; ++(i))
#define REPM(i, m, n) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; ++(i))
#define REPR(i, m, n) for (ll i = (m), i##_min = (ll)(n); i >= i##_min; --(i))
#define REPD(i, m, n, d) for (ll i = (m), i##_len = (ll)(n); i < i##_len; i += (d))
#define REPMD(i, m, n, d) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; i += (d))
#define REPI(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
#define ALL(x) begin(x), end(x)
#define SIZE(x) ((ll)(x).size())
#define PERM(c)                                                                                                        \
    sort(ALL(c));                                                                                                      \
    for (bool c##p = 1; c##p; c##p = next_permutation(ALL(c)))
#define UNIQ(v) v.erase(unique(ALL(v)), v.end());

#define endl '\n'
#define sqrt sqrtl
#define floor floorl
#define log2 log2l

constexpr ll INF = 1'010'000'000'000'000'017LL;
constexpr ll MOD = 1'000'000'007LL; // 1e9 + 7
constexpr ld EPS = 1e-12;
constexpr ld PI = 3.14159265358979323846;

template <typename T> istream &operator>>(istream &is, vc<T> &vec) { // vector 入力
    for (T &x : vec) is >> x;
    return is;
}
template <typename T> ostream &operator<<(ostream &os, vc<T> &vec) { // vector 出力 (for dump)
    os << "{";
    REP(i, 0, SIZE(vec)) os << vec[i] << (i == i_len - 1 ? "" : ", ");
    os << "}";
    return os;
}
template <typename T> ostream &operator>>(ostream &os, vc<T> &vec) { // vector 出力 (inline)
    REP(i, 0, SIZE(vec)) os << vec[i] << (i == i_len - 1 ? "\n" : " ");
    return os;
}

template <typename T, typename U> istream &operator>>(istream &is, pair<T, U> &pair_var) { // pair 入力
    is >> pair_var.first >> pair_var.second;
    return is;
}
template <typename T, typename U> ostream &operator<<(ostream &os, pair<T, U> &pair_var) { // pair 出力
    os << "(" << pair_var.first << ", " << pair_var.second << ")";
    return os;
}

// map, um, set, us 出力
template <class T> ostream &out_iter(ostream &os, T &map_var) {
    os << "{";
    REPI(itr, map_var) {
        os << *itr;
        auto itrcp = itr;
        if (++itrcp != map_var.end()) os << ", ";
    }
    return os << "}";
}
template <typename T, typename U> ostream &operator<<(ostream &os, map<T, U> &map_var) { return out_iter(os, map_var); }
template <typename T, typename U> ostream &operator<<(ostream &os, um<T, U> &map_var) {
    os << "{";
    REPI(itr, map_var) {
        auto [key, value] = *itr;
        os << "(" << key << ", " << value << ")";
        auto itrcp = itr;
        if (++itrcp != map_var.end()) os << ", ";
    }
    os << "}";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, set<T> &set_var) { return out_iter(os, set_var); }
template <typename T> ostream &operator<<(ostream &os, us<T> &set_var) { return out_iter(os, set_var); }
template <typename T> ostream &operator<<(ostream &os, pq<T> &pq_var) {
    pq<T> pq_cp(pq_var);
    os << "{";
    if (!pq_cp.empty()) {
        os << pq_cp.top(), pq_cp.pop();
        while (!pq_cp.empty()) os << ", " << pq_cp.top(), pq_cp.pop();
    }
    return os << "}";
}

// dump
#define DUMPOUT cerr
void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail> void dump_func(Head &&head, Tail &&... tail) {
    DUMPOUT << head;
    if (sizeof...(Tail) > 0) DUMPOUT << ", ";
    dump_func(move(tail)...);
}

// chmax (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>> bool chmax(T &xmax, const U &x, Comp comp = {}) {
    if (comp(xmax, x)) {
        xmax = x;
        return true;
    }
    return false;
}

// chmin (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>> bool chmin(T &xmin, const U &x, Comp comp = {}) {
    if (comp(x, xmin)) {
        xmin = x;
        return true;
    }
    return false;
}

// ローカル用
#define DEBUG_

#ifdef DEBUG_
#define DEB
#define dump(...)                                                                                                      \
    DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                                                                    \
            << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl                                        \
            << "    ",                                                                                                 \
        dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)
#endif

struct AtCoderInitialize {
    static constexpr int IOS_PREC = 15;
    static constexpr bool AUTOFLUSH = false;
    AtCoderInitialize() {
        ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
        cout << fixed << setprecision(IOS_PREC);
        if (AUTOFLUSH) cout << unitbuf;
    }
} ATCODER_INITIALIZE;

void Yn(bool p) { cout << (p ? "Yes" : "No") << endl; }
void YN(bool p) { cout << (p ? "YES" : "NO") << endl; }

/* #endregion */

/* #region TreeDP */

template <typename T> struct TreeDP {
    using merge_t = function<T(T, T, int, int)>;
    using add_root_t = function<T(T, int)>;
    struct edge_t {
        int to;
        ll cost;
        edge_t(int to, ll cost = 0) : to(to), cost(cost) {}
    };
    using graph_t = vc<vc<edge_t>>;

    merge_t merge;
    add_root_t add_root;
    int n;     //木の要素数
    const T e; //単位元
    vector<T> dp;
    graph_t G;

    TreeDP(merge_t merge, add_root_t add_root, int n, T e) : merge(merge), add_root(add_root), n(n), e(e) {
        dp.resize(n), G.resize(n);
    }

    void add_edge(int a, int b) { G[a].emplace_back(b); }

    void build() { dfs(0); }

    void dfs(int v, int p = -1) {
        T dp_cum = e;
        int deg = (int)G[v].size();
        for (int i = 0; i < deg; ++i) {
            int x = G[v][i].to;
            if (x == p) continue;
            dfs(x, v);
            dp_cum = merge(dp_cum, dp[x], v, x);
        }
        dp[v] = add_root(dp_cum, v);
    }
};

/* #endregion */

// Problem
void solve() {
    ll n;
    cin >> n;
    vll a(n), b(n);
    cin >> a >> b;
    vll u(n - 1), v(n - 1);
    REP(i, 0, n - 1) {
        cin >> u[i] >> v[i];
        --u[i], --v[i];
    }

    // 消されている場合のスコアは，頂点追加時に加算する
    // 頂点が残っている場合のスコアは，部分木追加時に計算する
    using data = pair<ll, ll>; // その頂点が消されている場合 / 残っている場合 のスコア
    auto merge = [&b](data dp_cum, data d, int v_parent, int v_child) -> data {
        auto [cum0, cum1] = dp_cum;
        auto [d0, d1] = d; // その部分木の頂点が消されている場合 / 残っている場合 のスコア
        // 頂点を残す場合，部分木が消えていたほうが得か，残っていた方が得かは，部分木ごとに決定可能
        // 頂点を消す場合，部分木が残っているかどうかは関係ない
        return {cum0 + max(d0, d1), cum1 + max(d0, d1 + b[v_parent] + b[v_child])};
    };
    auto add_root = [&a](data d, int v) -> data {
        auto [d0, d1] = d;
        return {d0 + a[v], d1};
    };
    TreeDP<data> tdp(merge, add_root, n, data({0, 0}));
    REP(i, 0, n - 1) {
        tdp.add_edge(u[i], v[i]);
        tdp.add_edge(v[i], u[i]);
    }
    tdp.build();

    // dump(tdp.dp);
    // dump(tdp.dp[0]);
    cout << max(tdp.dp[0].first, tdp.dp[0].second) << endl;
}

// entry point
int main() {
    solve();
    return 0;
}