#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
const int infm = -1e9;
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, d; cin>>n>>d;
vector<int> g[n + 1];
for (int i = 2; i <= n; i++){
int p; cin>>p; p++;
g[p].pb(i);
}
int k = ceil(1.0 * n / d);
vector<vector<int>> dp(n + 1, vector<int>(k + 1, infm));
function<void(int)> dfs = [&](int v){
for (int i: g[v]){
dfs(i);
}
int sm = 1;
for (int i: g[v]){
for (int j = k; j >= 0; j--){
if (dp[i][j] >= (d - 1)){
sm += j;
break;
}
}
for (int j = 0; j <= k; j++){
if (dp[i][j] == infm) continue;
int x = dp[i][j], y = max(x, d - x - 2), sum = j;
for (int t: g[v]){
if (t == i) continue;
for (int p = k; p >= 0; p--){
if (dp[t][p] >= y){
sum += p;
break;
}
}
}
dp[v][sum] = max(dp[v][sum], x + 1);
}
}
dp[v][sm] = max(dp[v][sm], 0);
dp[v][0] = 1e9;
};
dfs(1);
for (int j = k; j >= 0; j--){
if (dp[1][j] != infm){
cout<<j<<"\n";
return 0;
}
}
}
