using System;
using System.Linq;
using System.Collections.Generic;

namespace Contest
{
    class Program
    {
        static void Main(string[] args)
        {
            AGC009.B();
        }

        class AGC009
        {
            public static void A()
            {
                var N = Read.Int();
                var AB = Read.TupleLong(N);
                long count = 0;
                for(int i = N - 1; i >= 0; --i)
                {
                    var A = AB[i].Item1;
                    var B = AB[i].Item2;
                    var c = A + count - (A + count) / B * B;
                    count += c == 0 ? 0 : B - c;
                }
                Console.WriteLine(count);
            }
            public static void B()
            {
                var N = Read.Int();
                Dictionary<int, HashSet<int>> adj = new Dictionary<int, HashSet<int>>();
                for (int i = 0; i <= N; ++i)
                {
                    adj.Add(i, new HashSet<int>());
                }
                for (int i = 0; i < N - 1; ++i)
                {
                    var a = Read.Int();
                    adj[a].Add(i + 2);
                }
                var dist = Util.CalcDistance_OnTree(adj, N, 1);
                var order = Enumerable.Range(1, N).OrderBy(i => -dist[i]).ToArray();
                var deep = new int[N + 1];
                foreach(var v in order)
                {
                    if (adj[v].Count > 0)
                    {
                        var ds = adj[v].Select(i => deep[i]).OrderBy(x => -x).ToArray();
                        deep[v] = Enumerable.Range(0, adj[v].Count).Select(i => ds[i] + i + 1).Max();
                    }
                }
                Console.WriteLine(deep[1]);
            }
        }


        class Util
        {
            public static int[] CalcDistance_OnTree(Dictionary<int, HashSet<int>> adj, int N, int start)
            {
                var dist = Enumerable.Range(0, N + 1).Select(i => -1).ToArray();
                dist[start] = 0;
                Queue<int> queue = new Queue<int>();
                queue.Enqueue(start);
                while (queue.Count > 0)
                {
                    var v = queue.Dequeue();
                    foreach (var w in adj[v])
                    {
                        if (dist[w] < 0)
                        {
                            dist[w] = dist[v] + 1;
                            queue.Enqueue(w);
                        }
                    }
                }
                return dist;
            }
        }

        static class Read
        {
            static Queue<string> queue = new Queue<string>();
            static void Enqueue() { var ss = Console.ReadLine().Split(' '); foreach (var s in ss) { queue.Enqueue(s); } }
            public static int Int() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt32(queue.Dequeue()); }
            public static long Long() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt64(queue.Dequeue()); }
            public static string Str() { if (queue.Count == 0) { Enqueue(); } return queue.Dequeue(); }
            public static int[] IntN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt32(s)).ToArray(); }
            public static long[] LongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt64(s)).ToArray(); }
            public static string[] StrN() { return Console.ReadLine().Split(' '); }
            public static Tuple<int, int>[] TupleInt(int n) { List<Tuple<int, int>> list = new List<Tuple<int, int>>(); for (int i = 0; i < n; ++i) { var ab = Read.IntN(); list.Add(new Tuple<int, int>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<long, long>[] TupleLong(int n) { List<Tuple<long, long>> list = new List<Tuple<long, long>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<long, long>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<string, string>[] TupleStr(int n) { List<Tuple<string, string>> list = new List<Tuple<string, string>>(); for (int i = 0; i < n; ++i) { var ab = Read.StrN(); list.Add(new Tuple<string, string>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<double, double>[] TupleDouble(int n) { List<Tuple<double, double>> list = new List<Tuple<double, double>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<double, double>(ab[0], ab[1])); } return list.ToArray(); }
            public static long[,] LongMatrix(int r, int c)
            {
                var mat = new long[r, c];
                for (int i = 0; i < r; ++i)
                {
                    var x = Read.LongN();
                    for (int j = 0; j < c; ++j)
                    {
                        mat[i, j] = x[j];
                    }
                }
                return mat;
            }
            public static Dictionary<int, HashSet<int>> AdjacencyList(int N, int M)
            {
                Dictionary<int, HashSet<int>> dict = new Dictionary<int, HashSet<int>>();
                for (int i = 0; i <= N; ++i)
                {
                    dict.Add(i, new HashSet<int>());
                }
                for (int i = 0; i < M; ++i)
                {
                    var ab = Read.IntN();
                    dict[ab[0]].Add(ab[1]);
                    dict[ab[1]].Add(ab[0]);
                }
                return dict;
            }
            public static Dictionary<int, Dictionary<int, long>> AdjacencyListWithWeight(int N, int M)
            {
                Dictionary<int, Dictionary<int, long>> dict = new Dictionary<int, Dictionary<int, long>>();
                for (int i = 0; i <= N; ++i)
                {
                    dict.Add(i, new Dictionary<int, long>());
                }
                for (int i = 0; i < M; ++i)
                {
                    var ab = Read.IntN();
                    dict[ab[0]].Add(ab[1], ab[2]);
                    dict[ab[1]].Add(ab[0], ab[2]);
                }
                return dict;
            }
        }
    }
}


Measured memory_bytes: 44216