#include "job.h"
#include <vector>
#include <algorithm>
//#include <iostream>
using namespace std;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef long long llong;
int N;
VVI tree;
VI D, U;
vector<llong> sumD, sumU;
void dfs(int x) {
sumD[x] = D[x];
sumU[x] = U[x];
for (int y : tree[x]) {
dfs(y);
sumD[x] += sumD[y];
sumU[x] += sumU[y];
}
}
llong dfs2(int x, llong T) {
T += D[x];
llong res = U[x] * T;
sort(tree[x].begin(), tree[x].end(),
[&] (int i, int j) -> bool {
return sumD[i] * sumU[j] < sumD[j] * sumU[i];
});
for (int y : tree[x]) {
res += dfs2(y, T);
T += sumD[y];
}
return res;
}
long long scheduling_cost(vector<int> p, vector<int> u, vector<int> d) {
N = p.size();
tree = VVI(N);
::D = d;
::U = u;
for (int i = 1; i < N; ++i)
tree[ p[i] ].push_back(i);
sumD.assign(N, 0);
sumU.assign(N, 0);
dfs(0);
// for (int x = 0; x < N; ++x)
// cerr << x << ": " << sumD[x] << ' ' << sumU[x] << endl;
llong res = dfs2(0, 0);
return res;
}
