#include <iostream>
#include <vector>
using namespace std;
const int N = 2500;
vector<int> nei[N];
int dp[N][N], D, n, temp[N];
void dfs(int u){
dp[u][0] = 1;
for (int i : nei[u]){
dfs(i);
for (int i=0;i<=n;i++)
temp[i] = 0;
dp[i][D-1] = max(dp[i][D-1],dp[i][D]);
int mx = 0;
for (int d = 1;d<=D;d++){
mx = max(mx,dp[u][D - d]);
int k = min(d,D - d);
temp[k] = max(temp[k],dp[i][d-1] + mx);
}
mx = 0;
for (int d = 1;d<=D;d++)
temp[d] = max(temp[d],dp[i][d-1]);
for (int d=n;d + d >= D;d--){
mx = max(mx,dp[u][d]);
temp[d] = max(temp[d],mx + dp[i][d-1]);
}
for (int j=n;j>=0;j--){
dp[u][j] = max(dp[u][j],temp[j]);
dp[u][j] = max(dp[u][j],dp[u][j+1]);
}
}
}
int main(){
cin>>n>>D;
for (int i=2;i<=n;i++){
int p;
cin>>p;
nei[p + 1].push_back(i);
}
dfs(1);
int ans = 0;
for (int i=0;i<=n;i++)
ans = max(ans,dp[1][i]);
cout<<ans<<'\n';
}
// next
