#include <map>
#include <set>
#include <array>
#include <cmath>
#include <deque>
#include <bitset>
#include <random>
#include <string>
#include <vector>
#include <cassert>
#include <complex>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>

using namespace std;

const int MOD = 998244353;

int add(int a, int b) {
    return a + b >= MOD ? a + b - MOD : a + b;
}

int sub(int a, int b) {
    return a >= b ? a - b : a + MOD - b;
}

int mul(int a, int b) {
    return (1ll * a * b) % MOD;
}

int pw(int x, int n) {
    int res = 1;
    while (n) {
        if (n % 2 == 0) {
            x = mul(x, x);
            n /= 2;
        } else {
            res = mul(res, x);
            --n;
        }
    }
    return res;
}

const int MAXN = 1e5 + 100;
int p[MAXN];
int d[MAXN];
int fact[MAXN], invf[MAXN];
vector<int> val[MAXN];

vector<int> operator*(const vector<int>& a, const vector<int>& b) {
    vector<int> c(a.size());
    for (int i = 0; i < (int)a.size(); ++i) {
        for (int j = 0; j < (int)b.size() && i + j < (int)a.size(); ++j) {
            c[i + j] = add(c[i + j], mul(a[i], b[j]));
        }
    } 
    return c;
}


int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    fact[0] = 1;
    for (int i = 1; i < MAXN; ++i) {
        fact[i] = mul(fact[i - 1], i);
    }
    invf[MAXN - 1] = pw(fact[MAXN - 1], MOD - 2);
    for (int i = MAXN - 1; i > 0; --i) {
        invf[i - 1] = mul(invf[i], i);
    }
    int n;
    cin >> n;
    for (int i = 1; i < n; ++i) {
        cin >> p[i];
        --p[i];
    }
    d[0] = 0;
    for (int i = 1; i < n; ++i) {
        d[i] = d[p[i]] + 1;
    }

    for (int i = 0; i < n; ++i) {
        val[i].resize(d[i] + 2);
        for (int j = 0; j < d[i] + 2; ++j) {
            val[i][j] = invf[j];
        }
    }

    for (int i = n - 1; i > 0; --i) {
        vector<int> val1(val[i].begin() + 1, val[i].end());
        val[p[i]] = val[p[i]] * val1;
    }
    cout << mul(fact[n], val[0][1]) << "\n";
    
    return 0;
}