#include<stdio.h>
#include<algorithm>
#include<vector>
using namespace std;
vector<int>E[101000];
int n, m, D[101000], K, C[101000], w[101000];
void DFS(int a){
int i, r = 0;
C[a] = 1;
for (i = 0; i < E[a].size(); i++){
DFS(E[a][i]);
C[a] += C[E[a][i]];
w[i] = C[E[a][i]] - D[E[a][i]];
r += D[E[a][i]];
}
if (E[a].size() <= K){
D[a] = r;
return;
}
sort(w, w + E[a].size());
for (i = 0; i < E[a].size() - K; i++){
r += w[i];
}
D[a] = r;
}
int main(){
scanf("%d%d", &n, &m);
int i, a, be = 0, ed = n - 1, r;
for (i = 2; i <= n; i++){
scanf("%d", &a);
E[a].push_back(i);
}
while (be <= ed){
K = (be + ed) >> 1;
DFS(1);
if (n - D[1] >= m){
r = K;
ed = K - 1;
}
else be = K + 1;
}
printf("%d\n", r);
}
