#include <bits/stdc++.h>
#define int long long
using namespace std;
const int decalage = (1<<20);
int tab[2*decalage];
void modify(int ind, int new_val){
tab[ind] = new_val;
while (ind > 1){
ind/=2;
tab[ind] = max(tab[ind*2], tab[ind*2+1]);
}
}
int query(int l, int r){
if (l == r) return tab[l];
if (l%2 == 1){
return max(tab[l], query(l+1,r));
}
if (r%2 == 0){
return max(tab[r], query(l,r-1));
}
return query(l/2,r/2);
}
signed main(){
int nb_vertices, nb_fruits, nb_max, parent;
int location, day, juice;
cin >> nb_vertices >> nb_fruits >> nb_max;
for (int i = 2; i < nb_vertices+1; ++i){
cin >> parent;
}
vector<pair<int,int> > fruits;
int cnt = 0;
for (int i = 0; i < nb_fruits; ++i){
cin >> location >> day >> juice;
if (day <= nb_max) fruits.push_back(make_pair(location,day));
}
sort(fruits.rbegin(), fruits.rend());
// for (int i = 0; i < fruits.size(); ++i){
// cout<<fruits[i].first<<" "<<fruits[i].second<<" / ";
// }
// cout<<endl;
int lis[fruits.size()];
for (int i = 0; i < fruits.size(); ++i){
lis[i] = 0;
}
lis[0] = 1;
modify(fruits[0].second + decalage,1);
for (int i = 1; i < fruits.size(); ++i){
lis[i] = query(decalage,fruits[i].second+decalage) +1;
modify(fruits[i].second+decalage,lis[i]);
// for (int j = 0; j < fruits.size(); ++j){
// cout<<lis[j]<<" ";
// }
// cout<<endl;
}
for (int i = 0; i < fruits.size(); ++i){
cnt = max(cnt, lis[i]);
}
cout<<cnt;
}
