#pragma GCC target("avx") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include // #include // #include // #include // using namespace __gnu_pbds; // #include // namespace multiprecisioninteger = boost::multiprecision; // using cint=multiprecisioninteger::cpp_int; using namespace std; using ll=long long; #define double long double using datas=pair; using ddatas=pair; using tdata=pair; using vec=vector; using mat=vector; using pvec=vector; using pmat=vector; // using llset=tree,rb_tree_tag,tree_order_statistics_node_update>; #define For(i,a,b) for(i=a;i<(ll)b;++i) #define bFor(i,b,a) for(i=b,--i;i>=(ll)a;--i) #define rep(i,N) For(i,0,N) #define rep1(i,N) For(i,1,N) #define brep(i,N) bFor(i,N,0) #define brep1(i,N) bFor(i,N,1) #define all(v) (v).begin(),(v).end() #define allr(v) (v).rbegin(),(v).rend() #define vsort(v) sort(all(v)) #define vrsort(v) sort(allr(v)) #define uniq(v) (v).erase(unique(all(v)),(v).end()) #define endl "\n" #define eb emplace_back #define print(x) cout< ostream& operator<<(ostream& os,const pair& p){return os<<"("< ostream& operator<<(ostream& os,const vector& v){ os<<"{";ll i; rep(i,v.size()){ if(i)os<<","; os< inline bool chmax(T& a,T b){bool x=a inline bool chmin(T& a,T b){bool x=a>b;if(x)a=b;return x;} #ifdef DEBUG void debugg(){cout<void debugg(const T& x,const Args&... args){cout<<" "<0){ if(n&1)res=res*a%m; a=a*a%m; n>>=1; } return res; } ll gcd(ll a,ll b){if(!b)return abs(a);return (a%b==0)?abs(b):gcd(b,a%b);} ll lcm(ll a,ll b){return a/gcd(a,b)*b;} ll countdigits(ll n){ ll ans=0; while(n){n/=10;ans++;} return ans; } ll sumdigits(ll n){ ll ans=0; while(n){ans+=n%10;n/=10;} return ans; } class modmatrix{ mat a; ll H,W; public: modmatrix(mat& g):a(g){ H=g.size(); W=g[0].size(); } modmatrix(ll i,ll j):a(i,vec(j,0)){H=i;W=j;} modmatrix(ll n):a(n,vec(n,0)){H=W=n;} inline vec& operator [](int k){ return a[k]; } modmatrix operator +=(modmatrix b){ ll i,j; rep(i,this->H)rep(j,this->W){ (*this)[i][j]+=b[i][j]; if((*this)[i][j]>=mod)(*this)[i][j]-=mod; } return (*this); } modmatrix operator -=(modmatrix b){ ll i,j; rep(i,this->H)rep(j,this->W){ (*this)[i][j]-=b[i][j]; if((*this)[i][j]<0)(*this)[i][j]+=mod; } return (*this); } modmatrix operator *=(modmatrix b){ ll i,j,k; assert(this->W==b.H); modmatrix c(this->H,b.W); rep(i,this->H)rep(j,b.W){ c[i][j]=0; rep(k,this->W)c[i][j]+=(*this)[i][k]*b[k][j]%mod; c[i][j]%=mod; } (*this)=c; return (*this); } modmatrix operator ^=(ll K){ assert(this->H==this->W); modmatrix c(this->H); ll i; rep(i,this->H)c[i][i]=1; if(K&1)c*=(*this); while(K){ K>>=1; (*this)*=(*this); if(K&1)c*=(*this); } this->a.swap(c.a); return (*this); } modmatrix operator +(modmatrix c){ return modmatrix(*this)+=c; } modmatrix operator -(modmatrix c){ return modmatrix(*this)-=c; } modmatrix operator *(modmatrix c){ return modmatrix(*this)*=c; } modmatrix operator ^(ll K){ return modmatrix(*this)^=K; } modmatrix del(ll eh,ll ew){ ll i,j; mat res; rep(i,H){ if(i==eh)continue; res.resize(res.size()+1); rep(j,W){ if(j==ew)continue; res.back().eb(a[i][j]); } } return res; } ll determinant(){ assert(H==W); ll i,j,k,ans=1; auto b(a); rep(i,H){ if(!b[i][i]){ For(j,i+1,H)if(b[j][i]){ swap(b[i],b[j]); ans*=-1; break; } if(j==H)return 0; } (ans*=b[i][i])%=mod; For(j,i+1,W)(b[i][j]*=modinv(b[i][i]))%=mod; For(j,i+1,H)if(b[j][i]){ ll x=mod-b[j][i]; b[j][i]=0; For(k,i+1,W){ b[j][k]+=x*b[i][k]%mod; if(b[j][k]>=mod)b[j][k]-=mod; } } } if(ans<0)ans+=mod; return ans; } modmatrix inv(){ assert(H==W); ll i,j,k; modmatrix b(a),c(H,W); rep(i,H)c[i][i]=1; rep(i,H){ if(!b[i][i]){ For(j,i+1,H)if(b[j][i]){ swap(b[i],b[j]); swap(c[i],c[j]); break; } if(j==H)assert(false); } ll x=modinv(b[i][i]); rep(j,W){ (b[i][j]*=x)%=mod; (c[i][j]*=x)%=mod; } rep(j,H){ if(i==j)continue; if(b[j][i]){ x=mod-b[j][i]; rep(k,W){ b[j][k]+=x*b[i][k]%mod; if(b[j][k]>=mod)b[j][k]-=mod; c[j][k]+=x*c[i][k]%mod; if(c[j][k]>=mod)c[j][k]-=mod; } } } } return c; } void out(){ for(auto x:a)output(x); } }; struct unionfind{ private: int maxN; vector par,treesize; public:unionfind(int N) :maxN(N),par(N),treesize(N,1){ for(int i=0;itreesize[y])swap(x,y); par[x]=y; treesize[y]+=treesize[x]; return true; } bool unite(pair v){ return unite(v.first,v.second); } bool parcheck(int x,int y){ return root(x)==root(y); } bool parcheck(pair v){ return parcheck(v.first,v.second); } int size(int x){ return treesize[root(x)]; } void clear(){ treesize.assign(maxN,1); for(int i=0;i> groups(){ vector> res(maxN); for(int i=0;i> res2; for(vector x:res){ if(x.size())res2.eb(x); } return res2; } }; ll N,M,K,H,W,A,B,C,D; string s,t; ll ans; int main(){ // startupcpp(); // int codeforces;cin>>codeforces;while(codeforces--){ ll i,j; cin>>N>>M; mat g(N,vec(N,0)); unionfind dsu(N); rep(i,M){ cin>>A>>B; --A;--B; g[A][B]=g[B][A]=mod-1; dsu.unite(A,B); g[A][A]++;g[B][B]++; } if(dsu.size(0)==N){ print(0); modmatrix mg(g); // mg.out(); ans=mg.del(0,0).determinant(); debug(ans); rep1(i,N){ auto ch=mg.del(i,i); A=ch.determinant(); rep(j,i){ if(!g[i][j]){ ans+=ch.del(j,j).determinant()*A%mod; debug(ans); } } } ans%=mod; }else{ auto group=dsu.groups(); sort(all(group),[](auto l,auto r){return l.size()>r.size();}); for(auto x:group)ans+=(N-x.size())*x.size(); print(ans-(ll)group[0].size()*group[1].size()*2); while(group.size()>2&&group.back().size()!=group[0].size())group.pop_back(); vec ch; for(auto x:group){ if(x.size()==1){ ch.eb(1); continue; } modmatrix chg(x.size(),x.size()); rep(i,x.size())rep(j,x.size())chg[i][j]=g[x[i]][x[j]]; ch.eb(chg.del(0,0).determinant()); } debug(ch); ans=0; rep(i,group.size())For(j,i+1,group.size()){ ans+=(ll)group[i].size()*group[j].size(); } ans%=mod; for(auto x:ch)(ans*=x)%=mod; } print(ans); // } }