#include "september.h"
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
const int LG = 20;
int in[N], out[N], sub[N], up[N][LG], st[N * 4], lzy[N * 4], cnt[N], tmr = 0, n;
vector < int > adj[N];
void dfs(int u, int p){
sub[u] = 1;
in[u] = ++tmr;
up[u][0] = p;
for(int i = 1; i < LG; i++)
up[u][i] = up[up[u][i - 1]][i - 1];
for(auto v : adj[u]){
if(v == p)
continue;
dfs(v, u);
sub[u] += sub[v];
}
out[u] = tmr;
}
void relax(int v, int l, int r){
if(lzy[v] == -1)
return;
if(l != r){
lzy[v * 2] = lzy[v];
lzy[v * 2 + 1] = lzy[v];
}
st[v] = (r - l + 1) * lzy[v];
lzy[v] = -1;
}
void upd(int v, int l, int r, int ul, int ur, int x){
relax(v, l, r);
if(l > ur || r < ul)return;
if(l >= ul && r <= ur){
lzy[v] = x;
relax(v, l, r);
return;
}
int mid = (l + r) >> 1;
upd(v * 2, l, mid, ul, ur, x);
upd(v * 2 + 1, mid + 1, r, ul, ur, x);
st[v] = st[v * 2] + st[v * 2 + 1];
}
int ask(int v, int l, int r, int ql, int qr){
relax(v, l, r);
if(l > qr || r < ql)return 0;
if(l >= ql && r <= qr)return st[v];
int mid = (l + r) >> 1;
return ask(v * 2, l, mid, ql, qr) + ask(v * 2 + 1, mid + 1, r, ql, qr);
}
int upper(int u){
for(int i = LG - 1; i >= 0; i--){
int v = up[u][i];
if(ask(1, 1, n, in[v], in[v]) > 0)
u = v;
}
return u;
}
int solve(int n_, int m, vector < int > F, vector < vector < int > > S){
n = n_;
memset(lzy, -1, sizeof(lzy));
for(int i = 0; i < n; i++){
F[i]++;
adj[F[i]].push_back(i + 1);
}
for(int i = 0; i < m; i++){
for(int j = 0; j < S[i].size(); j++){
S[i][j]++;
}
}
dfs(1, 0);
int k = 0;
set < int > st;
for(int i = 0; i < n - 1; i++){
int node = S[0][i];
bool ok = ask(1, 1, n, in[node], in[node]);
if(ok == false){
cnt[node] = sub[node] - ask(1, 1, n, in[node], out[node]) - 1;
st.insert(node);
if(cnt[node] == 0)
st.erase(node);
upd(1, 1, n, in[node], out[node], 1);
}
else {
int up_node = upper(node);
cnt[up_node]--;
if(cnt[up_node] == 0)
st.erase(up_node);
}
k += (int)st.size() == 0;
}
return k;
}
/*
1
5 1
0 0 1 1
1 4 3 2
*/
