#include<bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using mint = atcoder::modint998244353;

vector<mint> &operator*=(vector<mint> &a, vector<mint> b){
	int n = a.size(), m = b.size();
	vector<mint> c(n + m - 1);
	for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			c[i + j] += a[i] * b[j];
		}
	}
	a = c;
    return a;
}

int main(){
	int N;
	cin >> N;
	vector<int> pare(N);
	for (int i = 1; i < N; i++) cin >> pare[i], pare[i]--;
	vector<vector<mint>> dp(N, {0, 1});
	for (int i = N - 1; i >= 0; i--){
		for (int j = (int)(dp[i].size()) - 1; j > 0; j--){
			dp[i][j - 1] += dp[i][j];
		}
		if (i) dp[pare[i]] *= dp[i];
	}
	mint ans = 0;
	for (auto x : dp[0]) ans += x;
	cout << ans.val() << endl;
}