#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define mkp make_pair
using namespace std;
const int inf=1e18,N=1e5+5,mod=998244353;
inline int rd(){
   int s=0,w=1;
   char ch=getchar();
   while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
   while(ch>='0'&&ch<='9')s=s*10+ch-'0',ch=getchar();
   return s*w;
}
int n,dep[N],sz[N];
vector<int> f[N];
vector<int> G[N];
int jc[N],inv[N];
int qp(int a,int b){
    int ans=1;
    while(b){
        if(b&1) ans=ans*a%mod;
        b>>=1; a=a*a%mod;
    }
    return ans;
}
void init(){
    jc[0]=1; for(int i=1;i<N;i++) jc[i]=jc[i-1]*i%mod;
    inv[N-1]=qp(jc[N-1],mod-2);
    for(int i=N-1;i;i--) inv[i-1]=inv[i]*i%mod;  
}
int merge(int x,int y){
    return jc[x+y]*inv[x]%mod*inv[y]%mod;
}
void dfs(int x,int fa){
    dep[x]=dep[fa]+1;  sz[x]=1;
    vector<int> tmp;
    f[x].resize(dep[x]+1,1);
    tmp.resize(dep[x]+1,0);
    int t_1=1;
    for(auto v:G[x]){
        if(v==fa) continue;
        dfs(v,x);
        sz[x]+=sz[v];
    }
    int now=1;
    for(auto v:G[x]){
        if(v==fa) continue;
        for(int i=0;i<=dep[x];i++) tmp[i]=0;
        for(int i=0;i<=dep[x];i++){
            for(int j=0;j<=i;j++){
                tmp[i]+=f[v][j]*f[x][i-j]%mod*merge(sz[v]+j,now+i-j)%mod;
                tmp[i]%=mod;
            }
            tmp[i]+=f[v][i+1]*t_1%mod*merge(now-1,sz[v]+i+1)%mod;
            tmp[i]%=mod;
        }
        t_1=merge(now-1,sz[v])*t_1%mod*f[v][0]%mod;
        for(int i=0;i<=dep[x];i++) f[x][i]=tmp[i];
        now+=sz[v];
    }
}
signed main(){
    //freopen(".in","r",stdin);
    //freopen(".out","w",stdout);
    n=rd(); init();
    for(int i=2;i<=n;i++) {
        int F=rd();
        G[F].push_back(i);
        G[i].push_back(F);
    }
    dfs(1,0);
    printf("%lld",f[1][0]);
    return 0;
}
/*
3
1 1

*/