#include<bits/stdc++.h>
#include<atcoder/modint>
using namespace std;

int main(){
  using mint=atcoder::modint998244353;
  int n;
  cin>>n;
  vector<int> p(n);
  p[0]=-1;
  vector<vector<int>> g(n);
  for (int i=1;i<n;i++){
    cin>>p[i],p[i]--;
    g[p[i]].push_back(i);
  }
  vector<vector<mint>> dp(n,vector<mint>(2));
  vector<int> sz(n);
  auto dfs=[&](auto dfs,int v)-> void {
    sz[v]=1;
    dp[v][0]=0;
    dp[v][1]=1;
    for (int u:g[v]){
      dfs(dfs,u);
      vector<mint> next(sz[v]+sz[u]+1);
      for (int i=0;i<=sz[v];i++) for (int j=0;j<=sz[u];j++) next[i+j]+=dp[v][i]*dp[u][j];
      swap(dp[v],next);
      sz[v]+=sz[u];
    }
    for (int i=sz[v];i>=1;i--) dp[v][i-1]+=dp[v][i];
  };
  dfs(dfs,0);
  mint ans=0;
  for (int i=0;i<=n;i++) ans+=dp[0][i];
  cout<<ans.val()<<endl;
}