import java.io.*;
import java.util.*;

class ContestReader {
  private BufferedReader reader;
  private StringTokenizer tokenizer;
  
  ContestReader(InputStream in) {
    reader = new BufferedReader(new InputStreamReader(in));
  }
  
  public String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }
  
  public int nextInt() {
    return Integer.parseInt(next());
  }
  
  public long nextLong() {
    return Long.parseLong(next());
  }
  
  public double nextDouble() {
    return Double.parseDouble(next());
  }
  
  public int[] nextIntArray(int n) {
    int[] array = new int[n];
    for (int i = 0; i < n; i++) {
      array[i] = nextInt();
    }
    return array;
  }
  
  public long[] nextLongArray(int n) {
    long[] array = new long[n];
    for (int i = 0; i < n; i++) {
      array[i] = nextLong();
    }
    return array;
  }
}



class Algorithm {
  private static void swap(Object[] list, int a, int b) {
    Object tmp = list[a];
    list[a] = list[b];
    list[b] = tmp;
  }
  
  public static <T extends Comparable<? super T>> boolean nextPermutation(T[] ts) {
    int rightMostAscendingOrderIndex = ts.length - 2;
    while (rightMostAscendingOrderIndex >= 0 &&
        ts[rightMostAscendingOrderIndex].compareTo(ts[rightMostAscendingOrderIndex + 1]) >= 0) {
      rightMostAscendingOrderIndex--;
    }
    if (rightMostAscendingOrderIndex < 0) {
      return false;
    }
    
    int rightMostGreatorIndex = ts.length - 1;
    while (ts[rightMostAscendingOrderIndex].compareTo(ts[rightMostGreatorIndex]) >= 0) {
      rightMostGreatorIndex--;
    }
    
    swap(ts, rightMostAscendingOrderIndex, rightMostGreatorIndex);
    for (int i = 0; i < (ts.length - rightMostAscendingOrderIndex - 1) / 2; i++) {
      swap(ts, rightMostAscendingOrderIndex + 1 + i, ts.length - 1 - i);
    }
    return true;
  }
}

class Node {
  int id;
  ArrayList<Node> children;
  
  Node(int id) {
    this.id = id;
    children = new ArrayList<>();
  }
  
  void addChild(Node node) {
    children.add(node);
  }
  
  public int getDepth() {
    int[] depth = new int[children.size()];
    for (int i = 0; i < children.size(); i++) {
      depth[i] = children.get(i).getDepth();
    }
    Arrays.sort(depth);
    int maxDepth = 0;
    for (int i = 0; i < depth.length; i++) {
      maxDepth = Math.max(maxDepth, depth[i] + depth.length - i);
    }
    return maxDepth;
  }
}

class Solver {
  public int solve(int n, int[] ops) {
    Node[] nodes = new Node[n + 1];
    for (int i = 1; i <= n; i++) {
      nodes[i] = new Node(i);
    }
    
    for (int id = 2; id <= n; id++) {
      nodes[ops[id - 2]].addChild(nodes[id]);
    }
    
    return nodes[1].getDepth();
  }
}

public class Main {
  private static void execute(ContestReader reader, PrintWriter out) {
    int n = reader.nextInt();
    int[] ops = reader.nextIntArray(n - 1);
    out.println(new Solver().solve(n, ops));
  }
  
  public static void main(String[] args) {
    ContestReader reader = new ContestReader(System.in);
    PrintWriter out = new PrintWriter(System.out);
    execute(reader, out);
    out.flush();
  }
}



Measured memory_bytes: 60852