#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

vector<vector<int>> children;
vector<long long> L[2];

void dfs( int u, const vector<long long>& T ){
    L[0][u] = 0;
    L[1][u] = T[u];
    for(int v : children[u]){
        dfs( v, T);
        L[0][u] += max( L[0][v], L[1][v] );
    }8
5 5 7 1 2 3 2 4
1
1
2
2
2
3
3
}

int main(){
    int n;
    cin >> n;

    vector<long long> T(n);
    for(int i=0; i<n; i++){
        cin >> T[i];
    }

    children.resize(n);
    for(int i=1; i<n; i++){
        int parent;
        cin >> parent;
        children[parent - 1].push_back(i);
    }
    L[0].assign(n, 0);
    L[1].assign(n, 0);

    dfs( 0, T );
    long long max_sum = max(L[0][0], L[1][0]);
    cout << max_sum;
}