#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
#define arr4 array<int, 4>
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);
}
const int S = 500;
if (d <= S){
vector<vector<int>> dp(n + 1, vector<int>(d));
function<void(int)> dfs = [&](int v){
for (int i: g[v]){
dfs(i);
}
dp[v][0] = 1;
for (int i: g[v]) dp[v][0] += dp[i][d - 1];
for (int x = 1; x < d; x++){
int sum = 0;
for (int i: g[v]){
sum += dp[i][max(x - 1, d - x - 1)];
}
for (int i: g[v]){
dp[v][x] = max(dp[v][x], (sum - dp[i][max(x - 1, d - x - 1)]) + dp[i][x - 1]);
}
}
for (int i = d - 2; i >= 0; i--){
dp[v][i] = max(dp[v][i], dp[v][i + 1]);
}
};
dfs(1);
cout<<dp[1][0]<<"\n";
return 0;
}
int k = ceil(1.0 * n / d) + 1;
vector<vector<int>> dp(n + 1, vector<int>(k, infm));
vector<int> f(n + 1);
function<void(int)> dfs = [&](int v){
for (int i: g[v]){
dfs(i);
}
vector<arr4> all;
for (int i: g[v]){
for (int j = 0; j < k; j++){
if (dp[i][j] == infm) continue;
int x = dp[i][j], y = max(x, d - x - 2);
all.pb({x, i, 0, j});
all.pb({y, -i, x, j});
}
}
auto cmp = [&](arr4 x, arr4 y){
if (x[0] != y[0]) return x[0] > y[0];
return x[1] > y[1];
};
sort(all.begin(), all.end(), cmp);
int sum = 0;
for (auto [x, y, t, vv]: all){
if (y > 0){
sum -= f[y];
f[y] = vv;
sum += f[y];
}
else {
y = -y;
int val = vv + sum - f[y];
dp[v][val] = max(dp[v][val], t + 1);
}
}
for (int i = k - 2; i >= 0; i--){
dp[v][i] = max(dp[v][i], dp[v][i + 1]);
}
dp[v][1] = max(dp[v][1], 0);
dp[v][0] = d;
for (int i: g[v]) f[i] = 0;
};
dfs(1);
for (int i = k - 1; i >= 0; i--){
if (dp[1][i] != infm){
cout<<i<<"\n";
return 0;
}
}
}
