import java.io.*; import java.util.*; public class Main { static final int MOD = 998244353; static ArrayList> graph = new ArrayList<>(); static int[] depths; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); for (int i = 0; i < n; i++) { graph.add(new ArrayList<>()); } for (int i = 1; i < n; i++) { graph.get(sc.nextInt() - 1).add(i); } depths = new int[n]; setDepth(0, 0); long ans = 1; for (int i = 1; i < n; i++) { ans *= depths[i]; ans %= MOD; } System.out.println(ans); } static void setDepth(int idx, int d) { depths[idx] = d; for (int x : graph.get(idx)) { setDepth(x, d + 1); } } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public String next() throws Exception { if (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }