#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int n, m, k, d[100001], w[100001], sz;
struct Node {
ll sum;
int lc, rc;
} mem[1 << 21];
vector<int> adj[100001];
void upd(int &n, int i, int v, int l, int r) {
if (not n) n = ++sz;
mem[n].sum += v;
if (l == r) return;
int m = (l + r) >> 1;
if (i <= m) upd(mem[n].lc, i, v, l, m);
else upd(mem[n].rc, i, v, m + 1, r);
}
void erase(int &n, int i, int &v, int l, int r) {
if (l > i or not v) return;
if (r <= i and mem[n].sum <= v) {
v -= mem[n].sum;
n = 0;
}
if (not n) return;
if (l == r) {
mem[n].sum -= v;
v = 0;
return;
}
int m = (l + r) >> 1;
erase(mem[n].rc, i, v, m + 1, r);
erase(mem[n].lc, i, v, l, m);
mem[n].sum = mem[mem[n].lc].sum + mem[mem[n].rc].sum;
}
int merge(int a, int b) {
if (not a or not b) return max(a, b);
mem[a].sum += mem[b].sum;
mem[a].lc = merge(mem[a].lc, mem[b].lc);
mem[a].rc = merge(mem[a].rc, mem[b].rc);
return a;
}
int dfs(int i) {
int root = 0;
for (int j: adj[i]) root = merge(root, dfs(j));
upd(root, -d[i], w[i], -k, -1);
erase(root, -d[i] - 1, w[i], -k, -1);
return root;
}
int main() {
cin >> n >> m >> k;
for (int i = 2; i <= n; ++i) {
int p;
cin >> p;
adj[p].emplace_back(i);
}
while (m--) {
int v;
cin >> v >> d[v] >> w[v];
}
cout << mem[dfs(1)].sum;
}
