#define _CRT_SECURE_NO_WARNINGS
/*
⣿⡟⡡⠾⠛⠻⢿⣿⣿⣿⡿⠃⣿⡿⣿⠿⠛⠉⠠⠴⢶⡜⣦⡀⡈⢿⣿
⡿⢀⣰⡏⣼⠋⠁⢲⡌⢤⣠⣾⣷⡄⢄⠠⡶⣾⡀⠀⣸⡷⢸⡷⢹⠈⣿
⡇⢘⢿⣇⢻⣤⣠⡼⢃⣤⣾⣿⣿⣿⢌⣷⣅⡘⠻⠿⢛⣡⣿⠀⣾⢠⣿
⣷⠸⣮⣿⣷⣨⣥⣶⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⡟⢁⡼⠃⣼⣿
⡟⠛⠛⠛⣿⠛⠛⢻⡟⠛⠛⢿⡟⠛⠛⡿⢻⡿⠛⡛⢻⣿⠛⡟⠛⠛⢿
⡇⢸⣿⠀⣿⠀⠛⢻⡇⠸⠃⢸⡇⠛⢛⡇⠘⠃⢼⣷⡀⠃⣰⡇⠸⠇⢸
⡇⢸⣿⠀⣿⠀⠛⢻⡇⢰⣿⣿⡇⠛⠛⣇⢸⣧⠈⣟⠃⣠⣿⡇⢰⣾⣿
⣿⣿⣿⠘⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⢋⣿⠙⣷⢸⣷⠀⣿⣿⣿
⣿⣿⣿⡇⢻⣿⣿⣿⡿⠿⢿⣿⣿⣿⠟⠋⣡⡈⠻⣇⢹⣿⣿⢠⣿⣿⣿
⣿⣿⣿⣿⠘⣿⣿⣿⣿⣯⣽⣉⣿⣟⣛⠷⠙⢿⣷⣌⠀⢿⡇⣼⣿⣿⣿
⣿⣿⣿⡿⢀⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣶⣤⡙⢿⢗⣀⣁⠈⢻⣿
*/
//#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
//Donald Trump pleese save this code
//Babahnineeleven will win IOI 2040
//Babahnineeleven will win IOI 2041
//Babahnineeleven will win IOI 2042
//Babahnineeleven will win IOI 2043
//Babahnineeleven will win IOI 2044
//Babahnineeleven will win IOI 2045
//Babahnineeleven will win IOI 2046
//Babahnineeleven will win IOI 2047
//Babahnineeleven will win IOI 2048
//Tanya Zadniprovska will win EGOI 2025
//Andrew Holod will NOT win IOI 2025
//Andrew Holod did not qualify to IOI 2025))))))))))
//Andrew Kholod will win ICPC WF 2026
//Andrew Pavlyk is best coder in Khmelnytski
//MoonSlay will NOT get Into IOI
#include <iostream>
#include <cstring>
#include <string>
#include <cmath>
#include <queue>
#include <bitset>
#include <stack>
#include <map>
#include <vector>
#include <set>
#include <algorithm>
#define endl '\n'
using namespace std;
FILE* stream;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair < int, int > pii;
typedef pair < ll, ll > pll;
typedef pair < ld, ld > pdd;
const long long DIM = 500007;
const ld eps = 1e-12;
const long long INF = 3e18;
const long long Bsize = 450;
const int mod = 1e9 + 7;
const long long NUMSZ = 500;
int solve(int n, int m, vector < int > f, vector < vector < int > > s) {
vector < vector < int > > v(n);
vector < vector < int > > fl(m, vector < int >(n, -1));
vector < int > cnt(m, 0);
for (int i = 1; i < n; i++) v[f[i]].push_back(i);
int res = 0;
int ptr = 0;
while (ptr < n - 1) {
for (int i = 0; i < m; i++) {
int ver = s[i][ptr];
if (f[ver] != -1 && fl[i][f[ver]] >= 0) {
if (fl[i][f[ver]] > 0) cnt[i]--;
fl[i][f[ver]]--;
if (fl[i][f[ver]] > 0) cnt[i]++;
}
fl[i][ver] = 0;
for (auto to : v[ver]) {
if (fl[i][to] == -1) fl[i][ver]++;
}
if (fl[i][ver] > 0) cnt[i]++;
}
ptr++;
bool flag = true;
for (int i = 0; i < m; i++) if (cnt[i] > 0) flag = false;
if (flag) {
res++;
}
}
return res;
}
/*
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifdef _DEBUG
freopen_s(&stream, "input.txt", "r", stdin);
freopen_s(&stream, "output.txt", "w", stdout);
#endif
cout << solve(5, 2, { -1, 0, 0, 1, 1 }, { {1, 2, 3, 4}, {4, 1, 2, 3} });
return 0;
}
*/
