#include<bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#include"debug.h"
#else
#define debug(...) void()
#endif
#define all(x) (x).begin(),(x).end()
template<class T>
auto ary(T *a,int l,int r){
	return vector<T>{a+l,a+1+r};
}
using ll=long long;
using ull=unsigned long long;
const int N=2e5+10,M=N*2,mod=1e9+7;
int n,m,k;
vector<int>to[N],tr[M];
vector<pair<int,int>>e[M];
int dft,dfn[N],low[N];
void add(int u,int v){
	tr[u].push_back(v),tr[v].push_back(u);
}
void tarjan(int u,int fa=0){
	static int top,stk[N];
	low[u]=dfn[u]=++dft,stk[++top]=u;
	for(int v:to[u])if(v^fa){
		if(!dfn[v]){
			tarjan(v,u),low[u]=min(low[u],low[v]);
			if(low[v]>=dfn[u]){
				add(++k,u);
				do add(k,stk[top]);while(stk[top--]^v);
			}
		}else low[u]=min(low[u],dfn[v]);
	}
}
int fa[M];
void make(int u){
	for(int v:tr[u])if(v^fa[u])fa[v]=u,make(v);
}
map<int,int>f[N];
bool chk(vector<int>&V,vector<pair<int,int>>&E){
	debug("chk",V,E);
	if(V.size()==2)return 1;
	for(int x:V)f[x].clear();
	for(auto [u,v]:E)f[u][v]=f[v][u]=1;
	queue<int>q;
	for(int x:V)if(f[x].size()==2)q.push(x);
	int cnt=0;
	for(int u;!q.empty();){
		u=q.front(),q.pop();
		if(f[u].size()!=2)continue;
		auto [v,x]=*f[u].begin();
		auto [w,y]=*f[u].rbegin();
		cnt+=(x==1)+(y==1),f[u].clear();
		f[v].erase(u),f[w].erase(u);
		f[v][w]=f[w][v]=2;
		for(int i:{v,w})if(f[i].size()==2)q.push(i);
	}
	if(cnt!=V.size())return 0;
	cnt=0;
	for(int x:V)cnt+=!f[x].empty();
	return cnt==2;
}
int main(){
	scanf("%d%d",&n,&m);
	vector<pair<int,int>>E(m);
	for(auto &[u,v]:E){
		scanf("%d%d",&u,&v);
		to[u].push_back(v),to[v].push_back(u);
	}
	k=n,tarjan(1),make(1);
	for(int u=1;u<=n;u++){
		for(int v:to[u])if(u<v){
			e[fa[fa[u]]==v?fa[u]:fa[v]].push_back({u,v});
		}
	}
	for(int i=k;i>n;i--){
		if(!chk(tr[i],e[i]))puts("0"),exit(0);
	}
	// debug("OK");
	int ans=n;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=tr[i].size();j++)ans=1ll*ans*j%mod;
	}
	for(int i=k;i>n;i--){
		if(tr[i].size()>2)ans=ans*2%mod;
	}
	cout<<ans<<endl;
	return 0;
}
#ifdef DEBUG
#include"debug.hpp"
#endif