import java.io.*;
import java.util.*;

public class Main {
    static final int MOD = 998244353;
    static ArrayList<ArrayList<Integer>> 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();
    }
}