#include <bits/stdc++.h>
using namespace std;
namespace Main {

#define ll long long
#define rep(i,l,r) for (int i(l), i##end(r); i <= i##end; ++i)
template <typename Tx> inline void read(Tx &x) {x = 0; bool f = 0; char ch = getchar(); while (ch < '0' || ch > '9') f ^= ch == '-', ch = getchar(); while (ch <= '9' && ch >= '0') x = x * 10 + ch - '0', ch = getchar(); if (f) x = -x;}
template <typename Tx, typename ...Ty> inline void read(Tx &x, Ty &...y) {read(x), read(y...);}
#define File(filename) freopen(filename".in", "r", stdin), freopen(filename".out", "w", stdout)

const int N = 1e5 + 9;
const int mod = 998244353;
mt19937 mtrnd(chrono::system_clock::now().time_since_epoch().count());
int n;
int p[N], sz[N], dep[N];
vector <int> f[N], G[N];

ll qpow(ll a, int x = mod - 2) {
    ll y = 1;
    for (; x; x >>= 1, a = a * a % mod) {
        if (x & 1) y = y * a % mod;
    }
    return y;
}

ll fac[N], ifac[N];
void init() {
    fac[0] = 1;
    for (int i = 1; i < N; ++i) fac[i] = fac[i - 1] * i % mod;
    ifac[N - 1] = qpow(fac[N - 1]);
    for (int i = N - 1; i > 0; --i) ifac[i - 1] = ifac[i] * i % mod;
}

#define sz(arr) ((int)(arr.size()))

inline void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
}

vector <int> product(vector <int> v1, vector <int> v2) {
    vector <int> res(v1.size(), 0);
    rep (i, 0, sz(v1) - 1) {
        rep (j, 0, sz(v2) - 1) {
            if (i + j < sz(v1)) {
                add(res[i + j], 1ll * v1[i] * v2[j] % mod);
            }
        }
    }
    return res;
}

void dfs(int u) {
    for (int v : G[u]) {
        dep[v] = dep[u] + 1;
        dfs(v);
    }
    sz[u] = 1;
    vector <int> (dep[u] + 1, 0).swap(f[u]);
    rep (i, 0, dep[u]) f[u][i] = ifac[i];
    for (int v : G[u]) {
        f[u] = product(f[u], f[v]);
        sz[u] += sz[v];
    }
    f[u].erase(f[u].begin());

    assert(sz(f[u]) == dep[u]);
}

void skymaths() {
    read(n);
    rep (i, 2, n) read(p[i]), G[p[i]].emplace_back(i);
    dep[1] = 1;
    dfs(1);
    printf("%lld\n", 1ll * f[1][0] * fac[n] % mod);
}

signed main() {
    double start_time = clock();
    // File("a");
    init();
    int T = 1;
    // scanf("%d", &T);
    while (T--) {
        skymaths();
    }
    cerr << "Time:" << (clock() - start_time) / CLOCKS_PER_SEC << "s\n";
    return 0;
}

}
signed main() {
    Main::main();
    return 0;
}