Summax1

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

const int N = 200005;

int n;
ll a[N];
vector<ll> adj[N];

ll dp[N];

void DFS(int u, int parent) {
    dp[u] = a[u];

    for(int v : adj[u]) {
        if(v != parent) {
        DFS(v, u);
        dp[u] = max(dp[v] + a[u], dp[u]);
        }
    }
}

int main() {
    //freopen("in.txt", "r", stdin);
    //freopen("Summax1.inp", "r", stdin);
    //freopen("Summax1.out","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n;
    for(int i = 1; i <= n; i++)
        cin >> a[i];
    for(int i = 1; i <= n; i++) {
        int u; cin >> u;
        if(u == 0) continue;

        adj[u].push_back(i);
        adj[i].push_back(u);
    }
    DFS(1, 0);

    cout << dp[1] << '\n';

    return 0;
}
/*
14
3 2 1 10 1 3 9 1 5 3 4 5 9 8
0 1 1 1 2 2 3 4 4 4 5 5 7 7
->22
*/