#include <bits/stdc++.h>
using namespace std;
int ts,js,ans,x,tot,head[20100],y,n,m,f[2010],v;
struct no{int val,nxt;}a[20101];
void jb(int x,int y){a[++tot]={y,head[x]},head[x]=tot;}
void sc(int t){
	if(t>n){ans++;return ;}
	sc(t+1);
	if(f[t]==1) return;
	for(int i=head[t];i;i=a[i].nxt) v=a[i].val,f[v]=1;
	sc(t+1);
	for(int i=head[t];i;i=a[i].nxt) v=a[i].val,f[v]=0;
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		cin>>x>>y;
		if(x>y)swap(x,y);
		jb(x,y);
	}
	sc(1);
	cout<<ans;
}