#include using namespace std; using ll = long long; using uint = unsigned int; #define rep(i,n) for(int i=0;i=0;i--) #define per1(i,n) for(int i=int(n);i>0;i--) #define all(c) c.begin(),c.end() #define si(x) int(x.size()) #define pb emplace_back #define fs first #define sc second template using V = vector; template using VV = vector>; template void chmax(T& x, U y){if(x void chmin(T& x, U y){if(y void mkuni(V& v){sort(all(v));v.erase(unique(all(v)),v.end());} template ostream& operator<<(ostream& o,const pair &p){ return o<<"("< ostream& operator<<(ostream& o,const vector &vc){ o<<"{"; for(const T& v:vc) o< struct ModInt{ using uint = unsigned int; using ll = long long; using ull = unsigned long long; constexpr static uint mod = mod_; uint v; ModInt():v(0){} ModInt(ll _v):v(normS(_v%mod+mod)){} explicit operator bool() const {return v!=0;} static uint normS(const uint &x){return (x [0 , mod-1] static ModInt make(const uint &x){ModInt m; m.v=x; return m;} ModInt operator+(const ModInt& b) const { return make(normS(v+b.v));} ModInt operator-(const ModInt& b) const { return make(normS(v+mod-b.v));} ModInt operator-() const { return make(normS(mod-v)); } ModInt operator*(const ModInt& b) const { return make((ull)v*b.v%mod);} ModInt operator/(const ModInt& b) const { return *this*b.inv();} ModInt& operator+=(const ModInt& b){ return *this=*this+b;} ModInt& operator-=(const ModInt& b){ return *this=*this-b;} ModInt& operator*=(const ModInt& b){ return *this=*this*b;} ModInt& operator/=(const ModInt& b){ return *this=*this/b;} ModInt& operator++(int){ return *this=*this+1;} ModInt& operator--(int){ return *this=*this-1;} ll extgcd(ll a,ll b,ll &x,ll &y) const{ ll p[]={a,1,0},q[]={b,0,1}; while(*q){ ll t=*p/ *q; rep(i,3) swap(p[i]-=t*q[i],q[i]); } if(p[0]<0) rep(i,3) p[i]=-p[i]; x=p[1],y=p[2]; return p[0]; } ModInt inv() const { ll x,y; extgcd(v,mod,x,y); return make(normS(x+mod)); } ModInt pow(ll p) const { if(p<0) return inv().pow(-p); ModInt a = 1; ModInt x = *this; while(p){ if(p&1) a *= x; x *= x; p >>= 1; } return a; } bool operator==(const ModInt& b) const { return v==b.v;} bool operator!=(const ModInt& b) const { return v!=b.v;} friend istream& operator>>(istream &o,ModInt& x){ ll tmp; o>>tmp; x=ModInt(tmp); return o; } friend ostream& operator<<(ostream &o,const ModInt& x){ return o<; //using mint = ModInt<1000000007>; V fact,ifact,invs; mint Choose(int a,int b){ if(b<0 || a=0;i--) ifact[i] = ifact[i+1] * (i+1); rep1(i,N-1) invs[i] = fact[i-1] * ifact[i]; } bool iszero(mint v){return v==0;} template struct Matrix{ int H,W; VV a; Matrix() : H(0),W(0){} Matrix(int H,int W) : H(H),W(W),a( VV(H,V(W)) ){} Matrix(const VV& v) : H(v.size()), W(v[0].size()), a(v){} static Matrix E(int n){ Matrix a(n,n); rep(i,n) a[i][i] = 1; return a; } V& operator[](int i){return a[i];} const V& operator[](int i) const {return a[i];} Matrix operator+(const Matrix& r) const { assert(H==r.H && W==r.W); VV v(H,V(W)); rep(i,H) rep(j,W) v[i][j] = a[i][j] + r.a[i][j]; return Matrix(v); } Matrix operator-(const Matrix& r) const { assert(H==r.H && W==r.W); VV v(H,V(W)); rep(i,H) rep(j,W) v[i][j] = a[i][j] - r.a[i][j]; return Matrix(v); } Matrix operator*(const Matrix& r) const { assert(W==r.H); VV v(H,V(r.W)); rep(i,H) rep(k,W) rep(j,r.W) v[i][j] += a[i][k] * r.a[k][j]; return Matrix(v); } Matrix& operator+=(const Matrix& r){return (*this)=(*this)+r;} Matrix& operator-=(const Matrix& r){return (*this)=(*this)-r;} Matrix& operator*=(const Matrix& r){return (*this)=(*this)*r;} Matrix pow(ll p) const { assert(H == W); Matrix a = E(H); Matrix x = *this; while(p){ if(p&1) a *= x; x *= x; p >>= 1; } return a; } friend ostream& operator<<(ostream &o,const Matrix& A){ rep(i,A.H){ rep(j,A.W) o< used(H); rep(j,var){ int i=0; while(i T det(VV a){ const int N = a.size(); if(N == 0) return T(1); assert(int(a[0].size()) == N); T ans(1); rep(i,N){ for(int j=i+1;j par,sz; UnionFind(int N){ par.assign(N,0); sz.assign(N,1); rep(i,N) par[i]=i; } int find(int x){ if(par[x]==x) return x; return par[x]=find(par[x]); } bool same(int x,int y){ return find(x)==find(y); } void unite(int x,int y){ x=find(x),y=find(y); if(x==y) return; par[y]=x; sz[x] += sz[y]; } }; int bsr(int x) { return 31 - __builtin_clz(x); } void ntt(bool type, V& c) { const mint G = 3; //primitive root int N = int(c.size()); int s = bsr(N); assert(1 << s == N); V a = c, b(N); rep1(i,s){ int W = 1 << (s - i); mint base = G.pow((mint::mod - 1)>>i); if(type) base = base.inv(); mint now = 1; for(int y = 0; y < N / 2; y += W) { for (int x = 0; x < W; x++) { auto l = a[y << 1 | x]; auto r = now * a[y << 1 | x | W]; b[y | x] = l + r; b[y | x | N >> 1] = l - r; } now *= base; } swap(a, b); } c = a; } V multiply_ntt(const V& a, const V& b) { int A = int(a.size()), B = int(b.size()); if (!A || !B) return {}; int lg = 0; while ((1 << lg) < A + B - 1) lg++; int N = 1 << lg; V ac(N), bc(N); for (int i = 0; i < A; i++) ac[i] = a[i]; for (int i = 0; i < B; i++) bc[i] = b[i]; ntt(false, ac); ntt(false, bc); for (int i = 0; i < N; i++) { ac[i] *= bc[i]; } ntt(true, ac); V c(A + B - 1); mint iN = mint(N).inv(); for (int i = 0; i < A + B - 1; i++) { c[i] = ac[i] * iN; } return c; } template struct Poly{ vector v; int size() const{ return v.size();} //deg+1 Poly(){} Poly(vector _v) : v(_v){shrink();} Poly& shrink(){ while(!v.empty()&&v.back()==D(0)) v.pop_back(); return *this; } D& operator[](int i){return v[i];} const D& operator[](int i) const {return v[i];} D at(int i) const{ return (i=size() && !x) return; while(i>=size()) v.push_back(D(0)); v[i]=x; shrink(); return; } D operator()(D x) const { D res = 0; int n = size(); D a = 1; rep(i,n){ res += a*v[i]; a *= x; } return res; } Poly operator+(const Poly &r) const{ int N=max(size(),r.size()); vector ret(N); rep(i,N) ret[i]=at(i)+r.at(i); return Poly(ret); } Poly operator-(const Poly &r) const{ int N=max(size(),r.size()); vector ret(N); rep(i,N) ret[i]=at(i)-r.at(i); return Poly(ret); } Poly operator-() const{ int N=size(); vector ret(N); rep(i,N) ret[i] = -at(i); return Poly(ret); } Poly operator*(const Poly &r) const{ if(size()==0||r.size()==0) return Poly(); return mul_ntt(r); // FFT or NTT ? } Poly operator*(const D &r) const{ int N=size(); vector ret(N); rep(i,N) ret[i]=v[i]*r; return Poly(ret); } Poly operator/(const D &r) const{ return *this * r.inv(); } Poly operator/(const Poly &y) const{ return div_fast(y); } Poly operator%(const Poly &y) const{ return rem_fast(y); // return rem_naive(y); } Poly operator<<(const int &n) const{ // *=x^n assert(n>=0); int N=size(); vector ret(N+n); rep(i,N) ret[i+n]=v[i]; return Poly(ret); } Poly operator>>(const int &n) const{ // /=x^n assert(n>=0); int N=size(); if(N<=n) return Poly(); vector ret(N-n); rep(i,N-n) ret[i]=v[i+n]; return Poly(ret); } bool operator==(const Poly &y) const{ return v==y.v; } bool operator!=(const Poly &y) const{ return v!=y.v; } Poly& operator+=(const Poly &r) {return *this = *this+r;} Poly& operator-=(const Poly &r) {return *this = *this-r;} Poly& operator*=(const Poly &r) {return *this = *this*r;} Poly& operator*=(const D &r) {return *this = *this*r;} Poly& operator/=(const Poly &r) {return *this = *this/r;} Poly& operator/=(const D &r) {return *this = *this/r;} Poly& operator%=(const Poly &y) {return *this = *this%y;} Poly& operator<<=(const int &n) {return *this = *this<>=(const int &n) {return *this = *this>>n;} Poly diff() const { int n = size(); if(n == 0) return Poly(); V u(n-1); rep(i,n-1) u[i] = at(i+1) * (i+1); return Poly(u); } Poly intg() const { int n = size(); V u(n+1); rep(i,n) u[i+1] = at(i) / (i+1); return Poly(u); } Poly pow(long long n, int L) const { // f^n, ignoring x^L,x^{L+1},.. Poly a({1}); Poly x = *this; while(n){ if(n&1){ a *= x; a = a.strip(L); } x *= x; x = x.strip(L); n /= 2; } return a; } /* [x^0~n] exp(f) = 1 + f + f^2 / 2 + f^3 / 6 + .. f(0) should be 0 O((N+n) log n) (N = size()) NTT, -O3 - N = n = 100000 : 200 [ms] - N = n = 200000 : 400 [ms] - N = n = 500000 : 1000 [ms] */ Poly exp(int n) const { assert(at(0) == 0); Poly f({1}), g({1}); for(int i=1;i<=n;i*=2){ g = (g*2 - f*g*g).strip(i); Poly q = (this->diff()).strip(i-1); Poly w = (q + g * (f.diff() - f*q)) .strip(2*i-1); f = (f + f * (*this - w.intg()).strip(2*i)) .strip(2*i); } return f.strip(n+1); } /* [x^0~n] log(f) = log(1-(1-f)) = - (1-f) - (1-f)^2 / 2 - (1-f)^3 / 3 - ... f(0) should be 1 O(n log n) NTT, -O3 1e5 : 140 [ms] 2e5 : 296 [ms] 5e5 : 640 [ms] 1e6 : 1343 [ms] */ Poly log(int n) const { assert(at(0) == 1); auto f = strip(n+1); return (f.diff() * f.inv(n)).strip(n).intg(); } /* [x^0~n] sqrt(f) f(0) should be 1 いや平方剰余なら何でもいいと思うけど探すのがめんどくさいので +- 2通りだけど 定数項が 1 の方 O(n log n) NTT, -O3 1e5 : 234 [ms] 2e5 : 484 [ms] 5e5 : 1000 [ms] 1e6 : 2109 [ms] */ Poly sqrt(int n) const { assert(at(0) == 1); Poly f = strip(n+1); Poly g({1}); for(int i=1; i<=n; i*=2){ g = (g + f.strip(2*i)*g.inv(2*i-1)) / 2; } return g.strip(n+1); } /* [x^0~n] f^-1 = (1-(1-f))^-1 = (1-f) + (1-f)^2 + ... f * f.inv(n) = 1 + x^n * poly f(0) should be non0 O(n log n) */ Poly inv(int n) const { assert(at(0) != 0); Poly f = strip(n+1); Poly g({at(0).inv()}); for(int i=1; i<=n; i*=2){ //need to strip!! g *= (Poly({2}) - f.strip(2*i)*g).strip(2*i); } return g.strip(n+1); } Poly exp_naive(int n) const { assert(at(0) == 0); Poly res; Poly fk({1}); rep(k,n+1){ res += fk; fk *= *this; fk = fk.strip(n+1) / (k+1); } return res; } Poly log_naive(int n) const { assert(at(0) == 1); Poly res; Poly g({1}); rep1(k,n){ g *= (Poly({1}) - *this); g = g.strip(n+1); res -= g / k; } return res; } Poly mul_naive(const Poly &r) const{ int N=size(),M=r.size(); vector ret(N+M-1); rep(i,N) rep(j,M) ret[i+j]+=at(i)*r.at(j); return Poly(ret); } Poly mul_ntt(const Poly &r) const{ return Poly(multiply_ntt(v,r.v)); } Poly mul_fft(const Poly &r) const{ return Poly(multiply_fft(v,r.v)); } Poly div_fast_with_inv(const Poly &inv, int B) const { return (*this * inv)>>(B-1); } Poly div_fast(const Poly &y) const{ if(size() res = v; res.resize(min(n,size())); return Poly(res); } Poly rev(int n = -1) const { //ignore x^n ~ -> return x^(n-1) * f(1/x) vector res = v; if(n!=-1) res.resize(n); reverse(all(res)); return Poly(res); } /* f.inv_div(n) = x^n / f f should be non0 O((N+n) log n) for division */ Poly inv_div(int n) const { n++; int d = size() - 1; assert(d != -1); if(n < d) return Poly(); Poly a = rev(); Poly g({at(d).inv()}); for(int i=1; i+d<=n; i*=2){ //need to strip!! g *= (Poly({2})-a.strip(2*i)*g).strip(2*i); } return g.rev(n-d); } friend ostream& operator<<(ostream &o,const Poly& x){ if(x.size()==0) return o<<0; rep(i,x.size()) if(x.v[i]!=D(0)){ o< interpolate(V x, V y){ assert(x.size() == y.size()); int N = x.size(); Poly f; rep(i,N){ Poly g({y[i]}); mint coef = 1; rep(j,N) if(j!=i){ g *= Poly({-x[j],1}); coef *= (x[i]-x[j]); } g *= coef.inv(); f += g; } return f; } int main(){ cin.tie(0); ios::sync_with_stdio(false); //DON'T USE scanf/printf/puts !! cout << fixed << setprecision(20); int N,M; cin >> N >> M; VV e(N,V(N)); UnionFind UF(N); rep(i,M){ int x,y; cin >> x >> y; x--,y--; e[x][y] = e[y][x] = 1; UF.unite(x,y); } V szs; rep(i,N) if(UF.find(i) == i){ szs.pb(UF.sz[i]); } auto numSpT = [&](VV e){ int n = si(e); V deg(n); rep(i,n) rep(j,n) deg[i] += e[i][j]; Matrix A(n-1,n-1); rep(i,n-1) rep(j,n-1){ if(i == j){ A[i][j] = deg[i]; }else{ A[i][j] = -e[i][j]; } } return det(A.a); }; if(si(szs) == 1){ V xs,ys; rep(x,N){ VV ee(N,V(N)); rep(i,N) rep(j,N) if(i != j){ if(e[i][j]) ee[i][j] = 1; else ee[i][j] = x; } xs.pb(x); ys.pb(numSpT(ee)); } auto f = interpolate(xs,ys); cout << 0 << endl; cout << f[0] + f[1] << endl; }else{ V f = szs; sort(all(f)); { int x = f[si(f)-1] + f[si(f)-2]; f.pop_back(); f.pop_back(); f.pb(x); int sqsum = 0; for(int v: f) sqsum += v*v; cout << N*N - sqsum << endl; } mint ans = 1; rep(s,N) if(UF.find(s) == s){ V vs; rep(v,N) if(UF.same(s,v)) vs.pb(v); int n = si(vs); VV ee(n,V(n)); rep(i,n) rep(j,n) ee[i][j] = e[vs[i]][vs[j]]; ans *= numSpT(ee); } sort(all(szs)); int K = si(szs); int way = 0; rep(i,K) rep(j,i) if(szs[i] == szs[K-1] && szs[j] == szs[K-2]) way++; show(szs); show(way); cout << ans * way * szs[K-1] * szs[K-2] << endl; } }