Problem:
Score : 800 points

Problem Statement

There are N towns in Snuke Kingdom, conveniently numbered 1 through N.
Town 1 is the capital.

Each town in the kingdom has a Teleporter, a facility that instantly transports a person to another place.
The destination of the Teleporter of town i is town a_i (1≤a_i≤N).
It is guaranteed that one can get to the capital from any town by using the Teleporters some number of times.

King Snuke loves the integer K.
The selfish king wants to change the destination of the Teleporters so that the following holds:

Starting from any town, one will be at the capital after using the Teleporters exactly K times in total.

Find the minimum number of the Teleporters whose destinations need to be changed in order to satisfy the king's desire.

Constraints

2≤N≤10^5

1≤a_i≤N

One can get to the capital from any town by using the Teleporters some number of times.

1≤K≤10^9

Input

The input is given from Standard Input in the following format:

N K
a_1 a_2 ... a_N

Output

Print the minimum number of the Teleporters whose destinations need to be changed in order to satisfy King Snuke's desire.

Sample Input 1

3 1
2 3 1

Sample Output 1

2

Change the destinations of the Teleporters to a = (1,1,1).

Sample Input 2

4 2
1 1 2 2

Sample Output 2

0

There is no need to change the destinations of the Teleporters, since the king's desire is already satisfied.

Sample Input 3

8 2
4 1 2 3 1 2 3 4

Sample Output 3

3

For example, change the destinations of the Teleporters to a = (1,1,2,1,1,2,2,4).

Solution in C++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <cassert>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>

using namespace std;

#define f first
#define s second
#define pb push_back
#define pp pop_back
#define mp make_pair
#define ll long long
#define ld double
#define ull unsigned long long
#define PI pair < int, int > 

const int N = 2050;
const int M = 123;
const ld Pi = acos(-1);
const ll Inf = 1e18;
const int inf = 1e9;
const int mod = 1e9 + 7;
const int Sz = 501;
const int MOD = 1e9 + 7;

void add(int &a, int b) {
  a += b;
  if (a >= mod) a -= mod;
}
int mult(int a, int b) {
  return 1ll * a * b % mod;
}
int sum(int a, int b) {
  add(a, b);
  return a;
}

int n, k, dp[N], a[N], cnt[N];
vector < int > g[N], gg[N];

void dfs(int v) {
  cnt[v] = dp[v] == k + 1;
  for (auto to : gg[v]) {
    dfs(to);
    cnt[v] += cnt[to];
  }
}
void solve() { 
  cin >> n >> k;
  for (int i = 1;i <= n;i++) {
    cin >> a[i];
    g[a[i]].pb(i);
    dp[i] = inf;
  }
  dp[1] = 0;
  queue < int > q;
  q.push(1);
  while(q.size()) {
    int v = q.front();
    q.pop();
    for (auto to : g[v]) {
      if (dp[to] > dp[v] + 1) {
        dp[to] = dp[v] + 1;
        gg[v].pb(to);
        q.push(to);
      }
    }
  }
  bool fail = 0;
  for (int i = 2;i <= n;i++) {
    if (dp[i] != k) {
      fail = 1;
    }
  }
  if (!fail) {
    cout << 0 << endl;
    return;
  }
  int ans = a[1] != 1;
  for (int i = 2;i <= n;i++) {
    if (dp[i] > k + 1) ans++;
  }
  dfs(1);
  for (auto to : gg[1]) if (cnt[to]) ans++;
  cout << ans << endl;
}

int main() {
  #ifdef wws
   freopen("in", "r", stdin);
  // freopen("out", "w", stdout);
  #endif 
  ios_base::sync_with_stdio(0);
  int tt = 1; 
  while(tt--) solve();
  return 0;
}