#include <bits/stdc++.h>
using namespace std;
const int maxn = 20;
long long n, m, x, y, ans, low, dp[maxn][1 << maxn];
bool f[maxn][maxn];
long long lowbit(long long x) {
  long long ret = 0;
  while (x) {
    if (x & 1)
      return ret;
    else
      ret++;
    x /= 2;
  }
}
int main() {
  scanf("%lld%lld", &n, &m);
  for (long long i = 1; i <= m; i++)
    scanf("%d%d", &x, &y), x--, y--, f[x][y] = f[y][x] = true;
  for (long long i = 0; i < n; i++) dp[i][1 << i] = 1;
  for (long long i = 1; i < (1 << n); i++) {
    long long minn = lowbit(i);
    for (long long j = 0; j < n; j++)
      if ((i & (1 << j)) && dp[j][i])
        for (long long k = minn; k < n; k++)
          if (f[j][k]) {
            if ((!(i & (1 << k))))
              dp[k][i | (1 << k)] += dp[j][i];
            else if (k == minn)
              ans += dp[j][i];
          }
  }
  printf("%lld\n", (ans - m) / 2);
  return 0;
}
