using System;
using System.Linq;
using System.Collections.Generic;
using System.Diagnostics;
using Debug = System.Diagnostics.Trace;
using SB = System.Text.StringBuilder;
using System.Numerics;
using static System.Math;
using static System.Console;
namespace Program
{
    public class Solver
    {
        Random rnd = new Random();
        public void Solve()
        {
            var n = ri;
            var G = Enumerate(n, x => new List<int>());
            for (int i = 1; i < n; i++)
            {
                var p = ri - 1;
                G[p].Add(i);
            }
            Func<int, int, KeyValuePair<int, long[,]>> dfs = null;
            dfs = (prev, cur) =>
            {
                var size = 1;
                //dp[sz,deg] = sz 個の連結成分からなり、次数が deg
                var ret = new long[2, 3];
                ret[1, 2] = 1;
                foreach (var t in G[cur])
                {
                    var sz = size;
                    var res = dfs(cur, t);
                    size += res.Key;
                    ret = merge(new int[] { sz, res.Key }, ret, res.Value);
                }
                return new KeyValuePair<int, long[,]>(size, ret);
            };
            var dp = dfs(-1, 0).Value;
            long ans = 0;
            var fact = new long[n + 1];
            fact[0] = 1;
            for (int i = 0; i < n; i++)
                fact[i + 1] = fact[i] * (i + 1) % MOD;
            for (int i = 0; i <= n; i++)
                for (int d = 0; d <= 2; d++)
                {
                    //Console.WriteLine($"{i} {d} {dp[i, d]}");
                    var v = dp[i, d] * fact[i] % MOD;
                    if (d != 2) v *= 2;
                    if ((n - i) % 2 == 0) ans += v;
                    else ans -= v;
                    ans %= MOD;
                }
            Console.WriteLine((ans + MOD) % MOD);

        }
        const long MOD = (long)1e9 + 7;

        //merge b to a
        long[,] merge(int[] sz, long[,] a, long[,] b)
        {
            var ret = new long[sz[0] + sz[1] + 1, 3];
            for (int i = 0; i <= sz[0]; i++)
                for (int j = 0; j <= sz[1]; j++)
                    for (int d = 0; d <= 2; d++)
                        for (int e = 0; e <= 2; e++)
                        {
                            var add = a[i, d] * b[j, e] % MOD;
                            if (add == 0) continue;
                            //Console.WriteLine($"{i} {j} {d} {e} {u} {v} {a[i, d, u]} {b[j, e, v]}");
                            update(ref ret[i + j, d], add * (e == 2 ? 1 : 2));
                            if (d != 0 && e != 0)
                            {
                                //Console.WriteLine($"@ i:{i} j:{j} d:{d} e:{e} u:{u} v:{v} a:{a[i, d, u]} b:{b[j, e, v]}");
                                update(ref ret[i + j - 1, d - 1], add);
                            }

                        }

            return ret;
        }
        void update(ref long u, long v)
        {
            u += v;
            u %= MOD;
        }

        const long INF = 1L << 60;
        static int[] dx = { -1, 0, 1, 0 };
        static int[] dy = { 0, 1, 0, -1 };
        int ri { get { return sc.Integer(); } }
        long rl { get { return sc.Long(); } }
        double rd { get { return sc.Double(); } }
        string rs { get { return sc.Scan(); } }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());

        static T[] Enumerate<T>(int n, Func<int, T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f(i);
            return a;
        }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(ie.ToArray()); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ")
    {
        return string.Join(st, ie);
    }
    static public void Main()
    {
        Console.SetOut(new Program.IO.Printer(Console.OpenStandardOutput()) { AutoFlush = false });
        var solver = new Program.Solver();
        solver.Solve();
        Console.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;

    public class Printer : StreamWriter
    {
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
    }

    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }

        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }

        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len)
            {
                ptr = 0;
                if ((len = str.Read(buf, 0, 1024)) <= 0)
                {
                    isEof = true;
                    return 0;
                }
            }
            return buf[ptr++];
        }

        public char Char()
        {
            byte b = 0;
            do b = read(); while ((b < 33 || 126 < b) && !isEof);
            return (char)b;
        }
        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read()) sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n' && b != 0; b = (char)read()) if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long() { return isEof ? long.MinValue : long.Parse(Scan()); }
        public int Integer() { return isEof ? int.MinValue : int.Parse(Scan()); }
        public double Double() { return isEof ? double.NaN : double.Parse(Scan(), CultureInfo.InvariantCulture); }
    }
}

#endregion


Measured memory_bytes: 32200