#include <bits/stdc++.h>
using namespace std;
const int MAXN = 200005;
vector<int>G[MAXN];
struct Obj {
int i, u, d;
bool operator <(const Obj& other) const {
bool ans;
if (u == 0) {
ans = 0;
} else {
if (other.u == 0) {
ans = 1;
} else {
if (1LL * d * other.u < 1LL * other.d * u)
ans = 1;
else
ans = 0;
}
}
return !ans;
}
};
long long scheduling_cost(vector<int>p, vector<int>u, vector<int>d) {
int n = p.size();
for (int i = 1; i < n; ++i)
G[p[i]].push_back(i);
long long ans = 0;
long long t = 0;
priority_queue<Obj>pq;
pq.push({0, u[0], d[0]});
while (!pq.empty()) {
Obj aux = pq.top();
pq.pop();
t += aux.d;
ans += t * aux.u;
for (auto it:G[aux.i])
pq.push({it, u[it], d[it]});
}
return ans;
}
/*int main() {
freopen("date.in", "r", stdin);
freopen("date.out", "w", stdout);
int n;
scanf("%d", &n);
vector<int>p(n), u(n), d(n);
for (int i = 0; i < n; ++i)
scanf("%d", &p[i]);
for (int i = 0; i < n; ++i)
scanf("%d", &u[i]);
for (int i = 0; i < n; ++i)
scanf("%d", &d[i]);
printf("%lld\n", scheduling_cost(p, u, d));
return 0;
}*/
