#include <bits/stdc++.h>
using namespace std;
int n, m;
long long ans, f[1 << 20][20];
bool Map[30][30];
int read() {
  int s = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    s = s * 10 + ch - '0';
    ch = getchar();
  }
  return s * f;
}
int main() {
  n = read(), m = read();
  for (int u, v, i = 1; i <= m; i++) {
    u = read() - 1, v = read() - 1;
    Map[u][v] = Map[v][u] = 1;
  }
  for (int i = 0; i < n; i++) f[1 << i][i] = 1;
  int maxn = (1 << n) - 1;
  for (int S = 0, sta; S <= maxn; S++) {
    for (int i = 0; i < n; i++)
      if (S & (1 << i)) {
        sta = i;
        break;
      }
    for (int i = sta; i < n; i++)
      for (int j = 0; j < n; j++) {
        if (!Map[i][j]) continue;
        if (!(S & (1 << i))) f[S | (1 << i)][i] += f[S][j];
        if (i == sta) ans += f[S][j];
      }
  }
  cout << (ans - m) / 2;
}
