#include <bits/stdc++.h>
using namespace std;
const int maxn = 25;
int n, m, full, mp[maxn][maxn], hed[1 << 19], lg[1 << 19], cnt[1 << 19];
long long dp[maxn][1 << 19], ans;
inline int read() {
  int res = 0, f_f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f_f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9')
    res = (res << 3) + (res << 1) - '0' + ch, ch = getchar();
  return res * f_f;
}
int main() {
  n = read(), m = read(), full = (1 << n) - 1;
  for (int i = 1; i <= m; i++) {
    int from = read(), to = read();
    mp[from][to] = mp[to][from] = 1;
  }
  lg[1] = 0;
  for (int mask = 0; mask <= full; mask++) {
    lg[mask] = lg[mask - 1];
    lg[mask] += (1 << lg[mask] + 1) <= mask ? 1 : 0;
    int state = mask;
    while (state) cnt[mask]++, state -= state & -state;
  }
  for (int i = 1; i <= n; i++) dp[i][1 << i - 1] = 1;
  for (int mask = 0; mask <= full; mask++)
    for (int i = 1; i <= n; i++) {
      if (!dp[i][mask]) continue;
      if (cnt[mask] > 1 && i == lg[mask & -mask] + 1) continue;
      if (cnt[mask] > 1 && mp[i][lg[mask & -mask] + 1])
        dp[lg[mask & -mask] + 1][mask] += dp[i][mask];
      for (int j = lg[mask & -mask] + 2; j <= n; j++) {
        if (!mp[i][j] || (mask & (1 << j - 1))) continue;
        dp[j][mask | (1 << j - 1)] += dp[i][mask];
      }
    }
  for (int i = 1; i <= n; i++)
    for (int mask = 0; mask <= full; mask++)
      if (cnt[mask] > 2 && i == lg[mask & -mask] + 1) ans += dp[i][mask] >> 1;
  printf("%lld\n", ans);
  return 0;
}
