/* -*- coding: utf-8 -*-
 *
 * 778.cc:  No.778 クリスマスツリー - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

typedef long long ll;
typedef vector<int> vi;

template <typename T, const int MAX_N>
struct BIT {
  int n;
  T bits[MAX_N + 1];
  BIT() {}

  void init(int _n) {
    n = _n;
    memset(bits, 0, sizeof(bits));
  }

  T sum(int x) {
    T s = 0;
    while (x > 0) {
      s += bits[x];
      x -= (x & -x);
    }
    return s;
  }

  void add(int x, T v) {
    while (x <= n) {
      bits[x] += v;
      x += (x & -x);
    }
  }
};

/* global variables */

int prts[MAX_N], cis[MAX_N], avs[MAX_N];
vi clds[MAX_N];
BIT<int,MAX_N> bit;

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  prts[0] = -1;
  for (int i = 1; i < n; i++) {
    scanf("%d", prts + i);
    clds[prts[i]].push_back(i);
  }

  memset(cis, -1, sizeof(cis));
  bit.init(n);
  ll sum = 0;

  for (int u = 0, rn = 0; u >= 0;) {
    if (cis[u] < 0)
      avs[u] = rn - bit.sum(u);

    if (++cis[u] >= clds[u].size()) {
      sum += (rn - bit.sum(u)) - avs[u];
      bit.add(u + 1, 1);
      rn++;
      u = prts[u];
    }
    else
      u = clds[u][cis[u]];
  }

  printf("%lld\n", sum);
  return 0;
}