#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<vvvl> vvvvl;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef pair<ll,ll> pl;
typedef pair<ll,pl> ppl;
typedef pair<ll,ppl> pppl;
typedef pair<ll,pppl> pppppl;
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define all(a) begin(a),end(a)
#define sz(a) (int)(a).size()
#define F first
#define S second
#define bs(A,x) binary_search(all(A),x)
#define lb(A,x) (ll)(lower_bound(all(A),x)-A.begin())
#define ub(A,x) (ll)(upper_bound(all(A),x)-A.begin())
#define cou(A,x) (ll)(upper_bound(all(A),x)-lower_bound(all(A),x))
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
//*
using mint=modint998244353;
const ll mod=998244353;
//*/
/*
using mint=modint1000000007;
const ll mod=1000000007;
//*/
//using mint=modint;
//*
typedef vector<mint> vm;
typedef vector<vm> vvm;
typedef vector<vvm> vvvm;
typedef vector<vvvm> vvvvm;
ostream&operator<<(ostream&os,mint a){os<<a.val();return os;}
istream&operator>>(istream&is,mint&a){int x;is>>x;a=mint(x);return is;}
//*/
template<typename T1,typename T2>ostream&operator<<(ostream&os,pair<T1,T2>p){os<<p.F<<" "<<p.S;return os;}
template<typename T1,typename T2>istream&operator>>(istream&is,pair<T1,T2>&p){is>>p.F>>p.S;return is;}
template<typename T>ostream&operator<<(ostream&os,vector<T>v){rep(i,0,sz(v))os<<v[i]<<(i+1!=sz(v)?" ":"");return os;}
template<typename T>istream&operator>>(istream&is,vector<T>&v){for(T&in:v)is>>in;return is;}
int main(){
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);
  ll N;cin>>N;
  vl P(N);
  rep(i,1,N)cin>>P[i];
  rep(i,1,N)P[i]--;
  vvl C(N);
  rep(i,1,N)C[P[i]].emplace_back(i);
  vvvm DP(N);
  rrep(v,0,N){
  	DP[v]=vvm{vm{1}};
  	for(auto u:C[v]){
  		vvm EP(max(sz(DP[v]),sz(DP[u])),vm(sz(DP[v][0])+sz(DP[u][0])-1));
  		rep(i,1,sz(DP[u]))rep(j,0,sz(DP[u][0]))DP[u][i][j]+=DP[u][i-1][j];
  		rep(i,1,sz(DP[v]))rep(j,0,sz(DP[v][0]))DP[v][i][j]+=DP[v][i-1][j];
  		rep(i,0,sz(EP))EP[i]=convolution(DP[v][min(i,sz(DP[v])-1)],DP[u][min(i,sz(DP[u])-1)]);
  		rrep(i,1,sz(EP))rep(j,0,sz(EP[i]))EP[i][j]-=EP[i-1][j];
  		DP[v]=EP;
  	}
  	vvm EP(sz(DP[v])+sz(DP[v][0]),vm(sz(DP[v][0])+1));
  	rep(i,0,sz(DP[v]))rep(j,0,sz(DP[v][0]))EP[i][j+1]=DP[v][i][j];
  	rep(i,0,sz(EP)-1)rep(j,1,sz(EP[i]))EP[i+1][j-1]+=EP[i][j];
  	DP[v]=EP;
  }
  mint ans=0;
  rep(j,0,sz(DP[0]))rep(k,0,sz(DP[0][j]))ans+=DP[0][j][k];
  cout<<ans<<endl;
  return 0;
}