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

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]] = atcoder::convolution(dp[i], dp[pare[i]]);
	}
	mint ans = 0;
	for (auto x : dp[0]) ans += x;
	cout << ans.val() << endl;
}