#if defined(_USE_PCH_)
#include "pch.hpp"
#else
#include <bits/stdc++.h>
#endif
#define RNG(V_, A_, B_, ...) for(int V_=(A_), V_##_END=(B_) __VA_OPT__(,) __VA_ARGS__; V_<=V_##_END; V_++)
#define IRNG(V_, A_, B_) for(int V_=(A_), V_##_END=(B_); V_>=V_##_END; V_--)
#ifdef _WIN32
#define long __int64
#endif
using namespace std;
const int MAXN=2e5+10,MOD=1e9+7;
int n,m,nnd,deg[MAXN],nsquare; vector<int> G[MAXN];
int dfn[MAXN],low[MAXN],dfnc,stk[MAXN],stkp,bel[MAXN];
vector<int> vec[MAXN];
void tarjan(int u){
    dfn[u]=low[u]=++dfnc; stk[++stkp]=u;
    for(int v:G[u]){
        if(!dfn[v]){
            tarjan(v);
            low[u]=min(low[u],low[v]);
            if(low[v]==dfn[u]){
                int c=0;
                deg[u]++,c++;
                ++nnd; vec[nnd].push_back(u);
                for(int w=0; w!=v; ) w=stk[stkp--],deg[w]++,c++,bel[w]=nnd,vec[nnd].push_back(w);
                nsquare+=c>2;
            }
        }else low[u]=min(low[u],dfn[v]);
    }
}
bool belcmp(int u,int v){ return bel[u]==bel[v]?u<v:bel[u]<bel[v]; }
set<pair<int,int>> G1[MAXN];
bool check(vector<int> U){
    sort(U.begin()+1,U.end());
    int rt=U[0];
    for(int u:U){
        if(u!=rt&&binary_search(G[u].begin(),G[u].end(),rt,belcmp)) G1[u].insert({rt,0}),G1[rt].insert({u,0});
        auto it=lower_bound(G[u].begin(),G[u].end(),U[1],belcmp); auto jt=upper_bound(G[u].begin(),G[u].end(),U.back(),belcmp);
        while(it!=jt) G1[u].insert({*(it++),0});
    }
    queue<int> q;
    for(int u:U){
        if(G1[u].size()==2) q.push(u);
    }
    int c=int(U.size());
    while(q.size()){
        int u=q.front(); q.pop();
        if(G1[u].empty()) continue;
//      cerr<<u<<"\n";
        assert(G1[u].size()==2);
        c--;
        int v1=G1[u].begin()->first,v2=next(G1[u].begin())->first;
        bool flag=false;
        assert(G1[v1].lower_bound({u,0})->first==u); assert(G1[v2].lower_bound({u,0})->first==u);
        G1[v1].erase(G1[v1].lower_bound({u,0})),G1[v2].erase(G1[v2].lower_bound({u,0}));
        auto it=G1[v1].lower_bound({v2,0});
        if(it!=G1[v1].end()&&it->first==v2) flag|=it->second,G1[v1].erase(it);
        G1[v1].insert({v2,1});
        it=G1[v2].lower_bound({v1,0});
        if(it!=G1[v2].end()&&it->first==v1) flag|=it->second,G1[v2].erase(it);
        G1[v2].insert({v1,1});
        if(G1[v1].size()==2) q.push(v1);
        if(G1[v2].size()==2) q.push(v2);
        G1[u].clear();
        if(flag) break;
    }
    for(int u:U) G1[u].clear();
    return c==2;
}
long fac[MAXN],ans=1;
int main(){
#if defined(_LOCAL_)
    freopen("in","r",stdin);
//  freopen("out","w",stdout);
#else
//  freopen("rated.in","r",stdin);
//  freopen("rated.out","w",stdout);
#endif
    ios::sync_with_stdio(false),cin.tie(nullptr),cout.tie(nullptr);
    cin>>n>>m;
    RNG(_,1,m,u,v) cin>>u>>v,G[u].push_back(v),G[v].push_back(u);
    tarjan(1);
    RNG(i,1,n) sort(G[i].begin(),G[i].end(),belcmp);
    RNG(i,1,nnd){
        if(vec[i].size()>2&&!check(move(vec[i]))){ cout<<0<<"\n"; return 0; }
    }
    ans=n;
    fac[0]=1; RNG(i,1,n) fac[i]=fac[i-1]*i%MOD;
    RNG(i,1,n) ans=ans*fac[deg[i]]%MOD;
//  cerr<<ans<<"\n";
    RNG(_,1,nsquare) ans=ans*2%MOD;
    cout<<ans<<"\n";

}