// From AgOH
//! AgOH TQL
//! stO AgOH Orz
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
struct E {
  int to, next;
} e[N];
int cnt_edge, head[N];
void addEdge(int u, int v) {
  e[++cnt_edge] = {v, head[u]};
  head[u] = cnt_edge;
}
int f[N];
void dfs(int u) {
  int sum = 0, max_f = 0;
  for (int i = head[u], v; i; i = e[i].next) {
    v = e[i].to;
    ++sum;
    dfs(v);
    max_f = max(max_f, f[v]);
  }
  f[u] = max_f + sum;
}
int main() {
  int n;
  cin >> n;
  for (int i = 2, fa; i <= n; ++i) {
    cin >> fa;
    addEdge(fa, i);
  }
  dfs(1);
  cout << f[1] << endl;
  return 0;
}