#include <bits/stdc++.h>
using namespace std;
const int N = 2'000 + 10;
int n, d;
vector<int> ad[N];
int f[N][N], maxV[N], maxU[N];
void dfs(int u, int p = -1) {
f[u][0] = 1;
for (const auto& v : ad[u]) {
dfs(v, u);
for (int i = d; i >= 0; --i) {
maxU[i] = max(f[u][i], maxU[i + 1]);
maxV[i] = max(f[v][i], maxV[i + 1]);
}
for (int i = 0; i <= d; ++i) {
auto& ret = f[u][i];
ret = max(ret, f[u][i] + maxV[max(i, d - i - 1)]);
if (i) ret = max(ret, f[v][i - 1] + maxU[max(i, d - i)]);
}
}
}
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> d;
for (int v = 1; v < n; ++v) {
int u; cin >> u;
ad[u].push_back(v);
}
dfs(0);
cout << *max_element(f[0], f[0] + d + 1) << "\n";
}
