#include "september.h"
#include <bits/stdc++.h>
using namespace std;
void dfs(int u, int v, vector<vector<int>> &adj, set<int> &disconnected, set<int> &cleared){
if(!cleared.count(u)){
disconnected.insert(u);
for(int i = 0; i < adj[u].size(); i ++){
dfs(adj[u][i], u, adj, disconnected, cleared);
}
}
}
int solve(int N, int M, vector<int> F, vector<vector<int>> S) {
vector<vector<int>> adj(N, vector<int>());
for(int i = 1; i < F.size(); i ++){
//cout << F[i] << " ";
adj[F[i]].push_back(i);
}
for(int i = 0; i < adj.size(); i ++){
for(int j = 0; j < adj[i].size(); j ++){
//cout << adj[i][j] << " ";
} //cout << "\n";
}
vector<int> record = S[0];
set<int> disconnected;
set<int> cleared;
int days = 0;
for(int i = 0; i < record.size(); i ++){
dfs(record[i], 0, adj, disconnected, cleared);
disconnected.erase(record[i]);
cleared.insert(record[i]);
//cout << disconnected.size() << " ";
if(disconnected.size() == 0){
days ++;
}
}
return days;
}
/*
g++ -std=gnu++17 -O2 -o september stub.cpp september.cpp
1
5 1
0 0 2 2
4 2 1 3
*/
