/***********************************************
* auth: tapilyoca *
* date: 02/16/2025 at 20:02:38 *
* dots: https://github.com/tapilyoca/dotilyoca *
***********************************************/
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<ll>;
/***********************************************/
void DFS(int curr, vector<bool> &vis, unordered_set<int> &wait, vector<vector<int>> adj){
vis[curr] = 1;
wait.insert(curr);
if(adj[curr].size() == 0){
return;
}
for(int c : adj[curr]){
DFS(c, vis, wait, adj);
}
}
int solve(int N, int M, vector<int> F, vector<vector<int>> S){
vector<vector<int>> kids(N+1);
for(int i = 1; i < N; i++){
kids[F[i]].push_back(i);
}
vector<bool> vis(N+1, 0);
unordered_set<int> waiting;
vector<int> freq(N,0);
int ans = 0;
for(int i = 0; i < N-1; i++){
for(int j = 0; j < M; j++){
int at = S[j][i];
waiting.insert(at);
freq[at]++;
if(!vis[at]){
// then we haven't touched this yet
// so set all of the children to be visited
DFS(at,vis,waiting,kids);
}
vis[at] = 1;
if(freq[at] == M){
waiting.erase(at);
}
}
if(waiting.size() == 0){
ans++;
}
}
return ans;
}
// int main(){
// ios::sync_with_stdio(false);
// cin.tie(NULL);
// int t = 1;
// // cin >> t;
// int n, m;
// cin >> n >> m;
// vector<int> a(n,0);
// for(int i = 0; i < n; i++){
// cin >> a[i];
// }
// vector<vector<int>> b;
// for(int i = 0; i < m; i++){
// vector<int> c(n-1,0);
// for(int j = 0; j < n-1; j++) cin >> c[j];
// b.push_back(c);
// }
// while(t--){
// // cerr << "here" << endl;
// cout << solve(n, m, a, b) << endl;
// }
// return 0;
// }
