#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define fi first
#define se second
typedef pair<ll, ll> P;
using VP = vector<P>;
using VVP = vector<VP>;
using VI = vector<ll>;
using VVI = vector<VI>;
using VVVI = vector<VVI>;
const int inf = 1e9 + 7;
const ll INF = 1LL << 61;
const ll mod = 1e9 + 7;

template <class T> inline bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template <class T> inline bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

int n;
vector<int> E[101010];
ll dp[101010][2];
ll a[101010], b[101010];

void dfs(int cu, int pa = -1) {
    dp[cu][0] = a[cu];
    dp[cu][1] = 0;
    for (ll to : E[cu])
        if (to != pa) {
            dfs(to, cu);
            dp[cu][0] += max(dp[to][0], dp[to][1]);
            dp[cu][1] += max(dp[to][0], dp[to][1] + b[cu] + b[to]);
        }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int i, j;
    cin >> n;
    for (i = 0; i < n; i++) cin >> a[i];
    for (i = 0; i < n; i++) cin >> b[i];
    for (i = 0; i < n - 1; i++) {
        ll u, v;
        cin >> u >> v;
        u--;
        v--;
        E[u].pb(v);
        E[v].pb(u);
    }
    dfs(0, -1);
    cout << max(dp[0][0], dp[0][1]) << endl;
}