#include "september.h"
#include <bits/stdc++.h>
int solve(int N, int M, std::vector<int> F, std::vector<std::vector<int>> S) {
std::vector<std::vector<int>> sizes(M, std::vector<int>(N));
std::vector<std::vector<bool>> is_leaf(M, std::vector<bool>(N));
std::vector<std::vector<int>> adj(N);
for (int i = 1; i < N; ++ i) {
for (int j = 0; j < M; ++ j) {
sizes[j][i]++;
sizes[j][F[i]]++;
}
adj[i].push_back(F[i]);
adj[F[i]].push_back(i);
}
std::vector<std::vector<int>> pos(M, std::vector<int>(N));
for (int j = 0; j < M; ++ j) {
for (int i = 0; i < N - 1; ++ i) {
pos[j][S[j][i]] = i;
}
}
std::vector<std::set<std::pair<bool, std::pair<int, int>>>> sts(M);
for (int i = 1; i < N; ++ i) {
for (int j = 0; j < M; ++ j) {
if (sizes[j][i] == 1) {
is_leaf[j][i] = true;
}
}
}
int ans = 0;
std::vector<std::vector<bool>> removed(M, std::vector<bool>(N));
std::vector<std::vector<bool>> queued(M, std::vector<bool>(N));
std::vector<int> listPtrs(M);
for (int i = 0; i < N - 1; ++ i) {
int end_at = i;
std::queue<int> q;
for (int j = 0; j < M; ++ j) {
q.push(S[j][listPtrs[j]]);
}
while (!q.empty()) {
int node = q.front();
q.pop();
for (int j = 0; j < M; ++ j) {
sts[j].insert({!is_leaf[j][node], {pos[j][node], node}});
queued[j][node] = true;
end_at = std::max(end_at, pos[j][node]);
}
for (int j = 0; j < M; ++ j) {
for (; listPtrs[j] <= end_at; ++ listPtrs[j]) {
q.push(S[j][listPtrs[j]]);
}
}
}
i = end_at;
int cur = 0;
for (int j = 0; j < M; ++ j) {
auto &st = sts[j];
while (!st.empty()) {
auto p = *st.begin();
if (p.first) {
break;
}
int node = p.second.second;
st.erase(st.begin());
for (auto &i : adj[node]) {
if (!removed[j][i]) {
sizes[j][i]--;
}
}
sizes[j][node] = 0;
removed[j][node] = true;
for (auto &i : adj[node]) {
if (i != 0 && sizes[j][i] == 1) {
is_leaf[j][i] = true;
if (queued[j][i]) {
st.erase({!false, {pos[j][i], i}});
st.insert({!true, {pos[j][i], i}});
}
}
}
}
if (st.empty()) {
cur++;
}
}
ans += cur == M;
}
return ans;
}
