/* -*- coding: utf-8 -*-
 *
 * 1878.cc:  No.1878 union-find の数え上げ - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 100000;
const int MOD = 998244353;

/* typedef */

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

/* global variables */

vi nbrs[MAX_N];
int ps[MAX_N], cis[MAX_N], ds[MAX_N];

/* subroutines */

/* main */

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

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

  int x = 1;
  ds[0] = 0;
  for (int u = 0; u >= 0;) {
    vi &nbru = nbrs[u];
    if (cis[u] < nbru.size()) {
      int v = nbru[cis[u]++];
      ds[v] = ds[u] + 1;
      u = v;
    }
    else {
      if (ds[u] > 1) x = (ll)x * ds[u] % MOD;
      u = ps[u];
    }
  }

  printf("%d\n", x);
  return 0;
}