// dadaaa QwQ
#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=1e5+10;
const ll P=998244353;
int n,dep[N],sz[N];
vector<int> e[N];
vector<ll> dp[N];
ll fac[N],finv[N];
ll qpow(ll x,ll k) {
	ll ans=1;
	while(k) {
		if(k&1) ans=ans*x%P;
		x=x*x%P;
		k/=2;
	}
	return ans;
}
ll C(ll x,ll y) {
	if(x<y||y<0) return 0;
	return fac[x]*finv[y]%P*finv[x-y]%P;
}
void dfs(int x) {
	dp[x].resize(dep[x]+2,1);
	vector<ll> tmp(dep[x]+2,0);
	sz[x]=0;
	for(int v:e[x]) {
		dep[v]=dep[x]+1;
		dfs(v);
		for(int i=0;i<=dep[x]+1;i++) {
			for(int j=0;j<=dep[v]&&i+j<=dep[x]+1;j++) {
				tmp[i+j]=(tmp[i+j]+dp[x][i]*dp[v][j]%P*C(sz[x]+sz[v]+i+j,sz[v]+j)%P)%P;
			}
		}
		sz[x]+=sz[v];
		for(int i=0;i<=dep[x]+1;i++) dp[x][i]=tmp[i],tmp[i]=0;
	}
	sz[x]++;
	for(int i=0;i<=dep[x];i++) dp[x][i]=dp[x][i+1];
}
int main() {
	cin>>n;
	for(int f,i=2;i<=n;i++) {
		cin>>f;
		e[f].push_back(i);
	}
	fac[0]=1;
	for(int i=1;i<=n;i++) fac[i]=fac[i-1]*i%P;
	finv[n]=qpow(fac[n],P-2);
	for(int i=n-1;i>=0;i--) finv[i]=finv[i+1]*(i+1)%P;
	dfs(1);
	cout<<dp[1][0]<<"\n";
	return 0;
}
/*
cd /home/nfls/workspace/QOJ7864
g++ code.cpp -o code -std=c++14 -Wall -O2
time ./code
*/