#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<ll, ll> pii;
typedef pair<ld, ld> pld;
ll n, m;
vector<pll> v;
int main() {
//freopen("in.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
cin >> n >> m;
while(m--){
ll t1, t2;
cin >> t1 >> t2;
--t1, --t2;
v.pb({t1, t2});
}
ll ret = 0;
for(ll bit = 0; bit < (1<<n); ++bit){
for(auto u : v)
if((bit&(1<<(u.ff))) > 0 && (bit&(1<<(u.ss))) > 0)
goto END;
++ret;
END:;
}
cout << ret << "\n";
}
