#include<bits/stdc++.h>
#define int long long
#define N 2000005
using namespace std;
int n,ans,a[N],maxx[N];
vector<int>e[N],o;
priority_queue<int>q[N];
void merge(int x,int y) {
	if(q[x].size()<q[y].size())swap(q[x],q[y]);
	while(q[y].size()){
		o.push_back(max(q[x].top(),q[y].top()));
		q[x].pop(),q[y].pop();
	}
	while(o.size())q[x].push(o.back()),o.pop_back();
}
void dfs(int x){
	for(unsigned int i=0;i<e[x].size();i++){
		dfs(e[x][i]);
		merge(x,e[x][i]);
	}
	q[x].push(a[x]);
}
signed main(){
	cin>>n;
	for(int i=1;i<=n;i++)cin>>a[i];
	for(int i=2;i<=n;i++){
		int x;cin>>x;
		e[x].push_back(i);
	}
	dfs(1);
	while(q[1].size()){
		ans+=q[1].top();
		q[1].pop();
	}
	cout<<ans;
	return 0;
}