#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i=0; i<n; i++)
#define pb push_back
#define int long long

int N;
int a[100010], b[100010];
vector<int> G[100010];
int memo[2][100010];

int dfs(int v, int pv, int f) {//f:0 vを消す, f:1 vを消さない
    if (memo[f][v]!=-1) return memo[f][v];
    int res = f==0 ? a[v]:0;
    if (f==0) {
        for (auto& nv:G[v]) {
            if (nv==pv) continue;
            res += max(dfs(nv, v, 0), dfs(nv, v, 1));
        }
    }
    else {
        for (auto& nv:G[v]) {
            if (nv==pv) continue;
            res += max(dfs(nv, v, 0), dfs(nv, v, 1)+b[v]+b[nv]);
        }
    }
    return memo[f][v] = res;
}

signed main() {
    cin.tie(0); ios::sync_with_stdio(false);
    cin >> N;
    rep(i, N) cin >> a[i];
    rep(i, N) cin >> b[i];
    rep(i, N-1) {
        int u, v; cin >> u >> v;
        G[u-1].pb(v-1);
        G[v-1].pb(u-1);
    }
    rep(i, 2) rep(j, N) memo[i][j] = -1;
    cout << max(dfs(0, -1, 0), dfs(0, -1, 1)) << endl;
}