#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using ld = long double;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int N; cin >> N;
    vector<vector<int>> G(N);
    rep(i,N-1) {
        int p; cin >> p; p--;
        G[p].push_back(i + 1);
    }

    vector<int> depth(N, 0);
    function<void(int)> dfs = [&](int v) -> void {
        for(int to : G[v]) {
            depth[to] = depth[v] + 1;
            dfs(to);
        }
    }; dfs(0);

    ll ans = 1;
    rep(i,N) if(i) ans = (ans * depth[i]) % 998244353;
    cout << ans << endl;
}