#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main()
{
    freopen("sweet.in", "r", stdin);
    freopen("sweet.out", "w", stdout);
    int n;
    cin >> n;
    vector<int> p(n + 1), c(n + 1);
    for (int i = 2; i <= n; i++) {
        cin >> p[i];
    }
    for (int i = 1; i <= n; i++) {
        cin >> c[i];
    }
    int ans = 2 * c[1];
    for (int i = 2; i <= n; i++) {
        ans = min(ans, 3 * c[i]);
    }
    cout << ans;
    return 0;
}