#include using namespace std; template inline void chmin(T1 &a,T2 b){if(a>b) a=b;} template inline void chmax(T1 &a,T2 b){if(a struct FixPoint : F{ FixPoint(F&& f):F(forward(f)){} template decltype(auto) operator()(Args&&... args) const{ return F::operator()(*this,forward(args)...); } }; template inline decltype(auto) MFP(F&& f){ return FixPoint{forward(f)}; } template struct Mint{ static constexpr T mod = MOD; T v; Mint():v(0){} Mint(signed v):v(v){} Mint(long long t){v=t%MOD;if(v<0) v+=MOD;} Mint pow(long long k){ Mint res(1),tmp(v); while(k){ if(k&1) res*=tmp; tmp*=tmp; k>>=1; } return res; } static Mint add_identity(){return Mint(0);} static Mint mul_identity(){return Mint(1);} Mint inv(){return pow(MOD-2);} Mint& operator+=(Mint a){v+=a.v;if(v>=MOD)v-=MOD;return *this;} Mint& operator-=(Mint a){v+=MOD-a.v;if(v>=MOD)v-=MOD;return *this;} Mint& operator*=(Mint a){v=1LL*v*a.v%MOD;return *this;} Mint& operator/=(Mint a){return (*this)*=a.inv();} Mint operator+(Mint a) const{return Mint(v)+=a;} Mint operator-(Mint a) const{return Mint(v)-=a;} Mint operator*(Mint a) const{return Mint(v)*=a;} Mint operator/(Mint a) const{return Mint(v)/=a;} Mint operator-() const{return v?Mint(MOD-v):Mint(v);} bool operator==(const Mint a)const{return v==a.v;} bool operator!=(const Mint a)const{return v!=a.v;} bool operator <(const Mint a)const{return v constexpr T Mint::mod; template ostream& operator<<(ostream &os,Mint m){os<>n; vector> G(n); vector indeg(n,0); for(int i=1;i>a>>b; a--;b--; G[a].emplace_back(b); indeg[b]++; } int rt=min_element(indeg.begin(),indeg.end())-indeg.begin(); using M = Mint; M ans{0}; MFP([&](auto dfs,int v,int d)->void{ for(int u:G[v]) dfs(u,d+1); ans+=M((long long)d*(d+1)/2); })(rt,0); cout<