#include <bits/stdc++.h>
using namespace std;
int n, m, x, y, adj[20][20];
long long dp[1 << 18][19];
long long f(int bit, int pos) {
  if (~dp[bit][pos]) return dp[bit][pos];
  long long ret = 0;
  for (int i = 0; i < n; i++)
    if (pos != i && adj[pos][i])
      if (i == n - 1)
        ret++;
      else if ((bit >> i) & 1)
        ret += f(bit ^ (1 << i), i);
  return dp[bit][pos] = ret;
}
int main() {
  cin >> n >> m;
  while (m--) {
    cin >> x >> y;
    x--;
    y--;
    adj[x][y] = 1;
    adj[y][x] = 1;
  }
  long long ret = 0;
  while (n > 1) {
    memset(dp, -1, sizeof(dp));
    for (int i = 0; i < n - 1; i++)
      if (adj[n - 1][i]) ret--;
    ret += f((1 << (n - 1)) - 1, n - 1);
    n--;
  }
  cout << ret / 2;
  return 0;
}
