object Main {
  def main(args: Array[String]): Unit = {
    val s = new Main()
    s.solve()
    s.out.flush()
  }
}

class Main {
  import java.io._
  import java.util.StringTokenizer

  import scala.collection.mutable
  import scala.util.Sorting
  import math.{abs, max, min}
  import mutable.{ArrayBuffer, ListBuffer}
  import scala.reflect.ClassTag

  val MOD = 1000000007
  val out = new PrintWriter(System.out)

  def solve(): Unit = {
    val N = ni()
    val from, to = Array.ofDim[Int](N - 1)
    rep(N - 1) { i =>
      from(i) = ni() - 1
      to(i) = i + 1
    }
    val t = packDGraph(N, from, to)
    val (_, _, queue) = traceBfs(t)

    val d = Array.ofDim[Int](N)

    def calcDepth(v: Int): Int = {
      val len = t(v).length
      if (len == 0) 0
      else {
        val childDepth = Array.ofDim[Int](len)
        rep(len) { i =>
          val u = t(v)(i)
          childDepth(i) = d(u)
        }
        Sorting.quickSort(childDepth)
        var mx = 0
        rep(len) { i =>
          mx = max(mx, childDepth(i) + len - i)
        }
        mx
      }
    }

    rep_r(N) { i =>
      val v = queue(i)
      d(v) = calcDepth(v)
    }

    out.println(d(0))
  }

  def packDGraph(n: Int, from: Array[Int], to: Array[Int]): Array[Array[Int]] = {
    val t = new Array[Array[Int]](n)
    val p = new Array[Int](n)
    val m = from.length
    rep(m)(i => p(from(i)) += 1)
    rep(n)(i => t(i) = new Array(p(i)))
    rep(m) { i =>
      p(from(i)) -= 1
      t(from(i))(p(from(i))) = to(i)
    }
    t
  }

  /**
    * @return (depth, parent, queue)
    */
  def traceBfs(g: Array[Array[Int]], rt: Int = 0): (Array[Int], Array[Int], Array[Int]) = {
    val n = g.length
    val INF = 1e9.toInt + 10
    val q, p = Array.ofDim[Int](n)
    q(0) = rt
    p(rt) = -1
    val d = Array.fill[Int](n)(INF)
    d(rt) = 0
    var cur = 0
    var last = 1
    while (cur < last) {
      val v = q(cur)
      rep(g(v).length) { i =>
        val u = g(v)(i)
        if (d(u) == INF) {
          d(u) = d(v) + 1
          p(u) = v
          q(last) = u
          last += 1
        }
      }
      cur += 1
    }
    (d, p, q)
  }

  class InputReader(val stream: InputStream) {
    private val reader = new BufferedReader(new InputStreamReader(stream), 32768)
    private var tokenizer: StringTokenizer = _

    def next(): String = {
      while (tokenizer == null || !tokenizer.hasMoreTokens)
        tokenizer = new StringTokenizer(reader.readLine)
      tokenizer.nextToken
    }

    def nextInt(): Int = next().toInt
    def nextLong(): Long = next().toLong
    def nextChar(): Char = next().charAt(0)
  }
  val sc = new InputReader(System.in)
  def ni(): Int = sc.nextInt()
  def nl(): Long = sc.nextLong()
  def nc(): Char = sc.nextChar()
  def ns(): String = sc.next()
  def ns(n: Int): Array[Char] = ns().toCharArray
  def na(n: Int, offset: Int = 0): Array[Int] = map(n)(_ => ni() + offset)
  def na2(n: Int, offset: Int = 0): (Array[Int], Array[Int]) = {
    val A1, A2 = Array.ofDim[Int](n)
    rep(n) { i =>
      A1(i) = ni() + offset
      A2(i) = ni() + offset
    }
    (A1, A2)
  }
  def nm(n: Int, m: Int): Array[Array[Int]] = {
    val A = Array.ofDim[Int](n, m)
    rep(n) { i =>
      rep(m) { j =>
        A(i)(j) = ni()
      }
    }
    A
  }
  def nal(n: Int): Array[Long] = map(n)(_ => nl())
  def nm_c(n: Int, m: Int): Array[Array[Char]] = map(n) (_ => ns(m))
  def rep(n: Int, offset: Int = 0)(f: Int => Unit): Unit = {
    var i = offset
    val N = n + offset
    while(i < N) { f(i); i += 1 }
  }
  def rep_r(n: Int, offset: Int = 0)(f: Int => Unit): Unit = {
    var i = n - 1 + offset
    while(i >= offset) { f(i); i -= 1 }
  }

  def map[@specialized A: ClassTag](n: Int, offset: Int = 0)(f: Int => A): Array[A] = {
    val res = Array.ofDim[A](n)
    rep(n)(i => res(i) = f(i + offset))
    res
  }


  def sumL(as: Array[Int]): Long = {
    var s = 0L
    rep(as.length)(i => s += as(i))
    s
  }

  def cumSum(as: Array[Int]) = {
    val cum = Array.ofDim[Int](as.length + 1)
    rep(as.length) { i =>
      cum(i + 1) = cum(i) + as(i)
    }
    cum
  }
}

Measured memory_bytes: 44824