using System;
using System.Linq;
using System.Collections.Generic;

namespace Contest
{
  class Program
  {
    static void Main(string[] args)
    {
      ABC054.C();
    }
    class ABC054
    {
      public static void A()
      {
        var A = Read.Int();
        var B = Read.Int();
        if (A == 1) { A = 14; }
        if (B == 1) { B = 14; }
        Console.WriteLine(A == B ? "Draw" : A > B ? "Alice" : "Bob");
      }
      public static void B()
      {
        var N = Read.Int();
        var M = Read.Int();
        var A = Enumerable.Range(0, N).Select(i => Read.Str()).ToArray();
        var B = Enumerable.Range(0, M).Select(i => Read.Str()).ToArray();
        for(int i = 0; i <= N - M; ++i)
        {
          for(int j = 0; j <= N - M; ++j)
          {
            bool ok = true;
            for(int k = 0; k < M; ++k)
            {
              for(int l = 0; l < M; ++l)
              {
                if (A[i + k][j + l] != B[k][l])
                {
                  ok = false;
                  break;
                }
              }
              if (!ok) { break; }
            }
            if (ok) { Console.WriteLine("Yes"); return; }
          }
        }
        Console.WriteLine("No");
      }
      public static void C()
      {
        var N = Read.Int();
        var M = Read.Int();
        var Adj = Read.AdjacencyList(N, M);
        var dp = new long[N, 1 << N];
        dp[0, 1] = 1;
        for(int i = 1; i < (1 << N) - 1; ++i)
        {
          for(int j = 0; j < N; ++j)
          {
            if(dp[j, i] == 0) { continue; }
            foreach (var v in Adj[j + 1])
            {
              var k = v - 1;
              if((i & (1 << k)) == 0)
              {
                dp[k, i + (1 << k)] += dp[j, i];
              }
            }
          }
        }
        Console.WriteLine(Enumerable.Range(0, N).Select(x => dp[x, (1 << N) - 1]).Sum());
      }
      public static void D()
      {
        var N = Read.Int();
        var MA = Read.Int();
        var MB = Read.Int();
        var ABC = Enumerable.Range(0, N).Select(i => Read.IntN()).ToArray();
        var dp = Util.Gen(401, 401, Int32.MaxValue);
        dp[0, 0] = 0;
        for(int i = 0; i < N; ++i)
        {
          var A = ABC[i][0];
          var B = ABC[i][1];
          var C = ABC[i][2];
          for (int j = 0; j <= i * 10; ++j)
          {
            for(int k = 0; k <= i * 10; ++k)
            {
              if (dp[j, k] < Int32.MaxValue)
              {
                dp[j + A, k + B] = Math.Min(dp[j + A, k + B], dp[j, k] + C);
              }
            }
          }
        }
        int min = Int32.MaxValue;
        for(int x = 1; ; ++x)
        {
          var A = MA * x;
          var B = MB * x;
          if(A>400 || B > 400) { break; }
          min = Math.Min(min, dp[A, B]);
        }
        Console.WriteLine(min == Int32.MaxValue ? -1 : min);
      }
    }

    class Util
    {
      public static T[,] Gen<T>(int r, int c, T v)
      {
        var matrix = new T[r, c];
        for (int i = 0; i < r; ++i)
        {
          for (int j = 0; j < c; ++j)
          {
            matrix[i, j] = v;
          }
        }
        return matrix;
      }
      public static long[] ASum(long[] array)
      {
        var res = new long[array.Length + 1];
        for (int i = 0; i < array.Length; ++i)
        {
          res[i + 1] = res[i] + array[i];
        }
        return res;
      }
      public static long[,] ASum(long[,] matrix)
      {
        var N = matrix.GetLength(0);
        var M = matrix.GetLength(1);
        var res = new long[N + 1, M + 1];
        for(int i = 0; i < N; ++i)
        {
          for(int j = 0; j < M; ++j)
          {
            res[i + 1, j + 1] = res[i, j + 1] + res[i + 1, j] - res[i, j] + matrix[i, j];
          }
        }
        return res;
      }
      public static Dictionary<T, long> Frequency<T>(T[] array)
      {
        var dict = new Dictionary<T, long>();
        foreach (var a in array)
        {
          if (!dict.ContainsKey(a)) { dict.Add(a, 0); }
          dict[a]++;
        }
        return dict;
      }
      public static long GCD(long a, long b)
      {
        while (b > 0)
        {
          var c = a % b;
          a = b;
          b = c;
        }
        return a;
      }
      public static HashSet<long> Divisor(long x)
      {
        var div = new HashSet<long>(); for (long p = 1; p * p <= x; ++p) { if (x % p == 0) { div.Add(p); } }
        foreach (var d in div.ToArray())
        {
          if (!div.Contains(x / d)) { div.Add(x / d); }
        }
        return div;
      }
      public static Dictionary<long, int> Factorize(long x)
      {
        var dict = new Dictionary<long, int>();
        long minp = 2;
        while (x > 1)
        {
          bool ok = false;
          for (long p = minp; p * p <= x; ++p)
          {
            if (x % p == 0)
            {
              if (!dict.ContainsKey(p))
              {
                dict.Add(p, 0);
              }
              dict[p]++;
              minp = p;
              x /= p;
              ok = true;
              break;
            }
          }
          if (!ok)
          {
            if (!dict.ContainsKey(x)) { dict.Add(x, 0); }
            dict[x]++;
            break;
          }
        }
        return dict;
      }


    }

    static class Read
{
static Queue<string> queue = new Queue<string>();
static void Enqueue() { var ss = Console.ReadLine().Split(' '); foreach (var s in ss) { queue.Enqueue(s); } }
public static int Int() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt32(queue.Dequeue()); }
public static long Long() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt64(queue.Dequeue()); }
public static string Str() { if (queue.Count == 0) { Enqueue(); } return queue.Dequeue(); }
public static int[] IntN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt32(s)).ToArray(); }
public static long[] LongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt64(s)).ToArray(); }
public static ulong[] ULongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToUInt64(s)).ToArray(); }
public static string[] StrN() { return Console.ReadLine().Split(' '); }
public static Tuple<int, int>[] TupleInt(int n) { List<Tuple<int, int>> list = new List<Tuple<int, int>>(); for (int i = 0; i < n; ++i) { var ab = Read.IntN(); list.Add(new Tuple<int, int>(ab[0], ab[1])); } return list.ToArray(); }
public static Tuple<long, long>[] TupleLong(int n) { List<Tuple<long, long>> list = new List<Tuple<long, long>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<long, long>(ab[0], ab[1])); } return list.ToArray(); }
public static Tuple<string, string>[] TupleStr(int n) { List<Tuple<string, string>> list = new List<Tuple<string, string>>(); for (int i = 0; i < n; ++i) { var ab = Read.StrN(); list.Add(new Tuple<string, string>(ab[0], ab[1])); } return list.ToArray(); }
public static Tuple<double, double>[] TupleDouble(int n) { List<Tuple<double, double>> list = new List<Tuple<double, double>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<double, double>(ab[0], ab[1])); } return list.ToArray(); }
public static long[,] LongMatrix(int r, int c) { var mat = new long[r, c]; for (int i = 0; i < r; ++i) { var x = Read.LongN(); for (int j = 0; j < c; ++j) { mat[i, j] = x[j]; } } return mat; }
public static Dictionary<int, HashSet<int>> AdjacencyList(int N, int M, bool isDirectional = false)
{
Dictionary<int, HashSet<int>> dict = new Dictionary<int, HashSet<int>>();
for (int i = 0; i <= N; ++i) { dict.Add(i, new HashSet<int>()); }
        for (int i = 0; i < M; ++i) { var ab = Read.IntN(); if (!dict[ab[0]].Contains(ab[1])) { dict[ab[0]].Add(ab[1]); } if (!isDirectional && !dict[ab[1]].Contains(ab[0])) { dict[ab[1]].Add(ab[0]); } }
        return dict;
}
public static Dictionary<int, Dictionary<int, long>> AdjacencyListWithWeight(int N, int M)
{
Dictionary<int, Dictionary<int, long>> dict = new Dictionary<int, Dictionary<int, long>>(); for (int i = 0; i <= N; ++i) { dict.Add(i, new Dictionary<int, long>()); }
for (int i = 0; i < M; ++i) { var ab = Read.IntN(); dict[ab[0]].Add(ab[1], ab[2]); dict[ab[1]].Add(ab[0], ab[2]); }
return dict;
}
}
    }
}


Measured memory_bytes: 20600