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

const long long INF = 1e18;

long long place_police(vector<int> par, vector<long long> wpar, vector<long long> weights) {
    par.insert(par.begin(), -1);
    wpar.insert(wpar.begin(), -1);
    int n = par.size();
    int k = weights.size();

    vector<vector<int>> adj(n);
    for (int u = 1; u < n; u++) {
        adj[par[u]].push_back(u);
    }

    int cnt = 0;
    auto dfs = [&](auto self, int u) -> vector<vector<vector<long long>>> {
        if (adj[u].empty()) {
            vector<vector<vector<long long>>> res(2, vector<vector<long long>>(3, vector<long long>(3, INF)));
            cnt++;
            res[0][0][0] = 0;
            res[1][1][1] = 0;
            return res;
        }

        vector<vector<vector<long long>>> res(2, vector<vector<long long>>(3, vector<long long>(3, 0)));
        bool first = true;
        for (int v : adj[u]) {
            auto get = self(self, v);
            long long cost = weights[cnt - 1];
            vector<vector<vector<long long>>> upd(2, vector<vector<long long>>(3, vector<long long>(3, INF)));
            for (int cu = 0; cu < 2; cu++) {
                for (int lu = 0; lu < 3; lu++) {
                    for (int ru = 0; ru < 3; ru++) {
                        for (int cv = 0; cv < 2; cv++) {
                            for (int lv = 0; lv < 3; lv++) {
                                for (int rv = 0; rv < 3; rv++) {
                                    upd[cu][first ? 2 : lu][2] = min(upd[cu][lu][2], res[cu][lu][ru] + get[cv][lv][rv] + wpar[v]);
                                    if (cu != cv) {
                                        upd[cu][lu][rv] = min(upd[cu][lu][rv], res[cu][lu][ru] + get[cv][lv][rv] + cost * (ru <= 1 && lv <= 1 && ru == lv));
                                    }
                                }
                            }
                        }
                    }
                }
            }
            res = upd;
            first = false;
        }

        return res;
    };
    auto res = dfs(dfs, 0);

    long long ans = INF;

    if (k & 1) {
        for (int c = 0; c < 2; c++) {
            for (int l = 0; l < 3; l++) {
                for (int r = 0; r < 3; r++) {
                    if (l == 2 || r == 2 || l != r) {
                        ans = min(ans, res[c][l][r]);
                    }
                }
            }
        }
    } else {
        for (int c = 0; c < 2; c++) {
            for (int l = 0; l < 3; l++) {
                for (int r = 0; r < 3; r++) {
                    ans = min(ans, res[c][l][r]);
                }
            }
        }
    }

    return ans;
}

//template<class T>
//void read(vector<T> &a) {
//    if (a.empty()) {
//        T x;
//        while (cin >> x) {
//            if (x == -1) break;
//            a.push_back(x);
//        }
//    } else {
//        for (T &x : a) {
//            cin >> x;
//        }
//    }
//}
//int main() {
//    ios::sync_with_stdio(false);
//    cin.tie(nullptr);
//    int n;
//    cin >> n;
//    vector<int> par(n - 1);
//    vector<long long> wpar(n - 1);
//    vector<long long> weights;
//    read<int>(par);
//    read<long long>(wpar);
//    read<long long>(weights);
//    cout << place_police(par, wpar, weights);
//}