#include <bits/stdc++.h>
using namespace std;
#define int long long
#define inf 0x3F3F3F3F3F3F3F3F
const int MXN = 1e5 + 5;
const int LOG = 20;
const int mod = 1e9 + 7;
vector<int> adj[MXN];
int msk, cyc, c;
int col[MXN], par[MXN];
void dfs(int a)
{
c++;
col[a] = 1;
for (int v : adj[a])
{
if (!(msk >> v & 1)) continue;
if (v == par[a]) continue;
if (col[v] == 1) cyc = 1;
if (!col[v])
{
par[v] = a;
dfs(v);
}
}
col[a] = 2;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, m;
cin >> n >> m;
for (int i = 1; i <= m; i++)
{
int u, v;
cin >> u >> v;
u--, v--;
adj[u].push_back(v);
adj[v].push_back(u);
}
int res = 0;
for (msk = 1; msk < (1LL << n); msk++)
{
c = 0, cyc = 0;
for (int i = 0; i < n; i++)
{
if (msk >> i & 1)
{
dfs(i);
break;
}
}
for (int i = 0; i < n; i++) par[i] = 0, col[i] = 0;
if (c == __builtin_popcount(msk) && !cyc) res++;
}
cout << res << '\n';
}
