import std.stdio, std.conv, std.string, std.array, std.range, std.algorithm, std.container;
import std.math, std.random, std.bigint, std.datetime, std.format;
void main(string[] args){ if(args.length > 1) if(args[1] == "-debug") DEBUG = 1; solve(); }
void log()(){ writeln(""); } void log(T, A ...)(T t, lazy A a){ if(DEBUG) write(t, " "), log(a); } bool DEBUG = 0; 
string read(){ static string[] ss; while(!ss.length) ss = readln.chomp.split; string res = ss[0]; ss.popFront; return res; }
// ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- //

void solve(){
	
	int n = read.to!int;
	
	Node[] nodes;
	foreach(i; 0 .. n) nodes ~= new Node(i);
	
	foreach(i; 1 .. n){
		int a = read.to!int - 1;
		Node par = nodes[a];
		par.sons ~= nodes[i];
	}
	
	int ans = nodes[0].value;
	
	ans.writeln;
	
}

class Node{
	int id;
	int _value;
	Node[] sons;
	bool hasValue = 0;
	this(int id){
		this.id = id;
	}
	int value(){
		if(! hasValue){
			_value = 0;
			sons.sort!"a.value>b.value"();
			foreach(i, nd; sons){
				_value = max(_value, nd.value + i + 1).to!int;
			}
		}
		return _value;
	}
}